Devices, systems and methods to improve placement and prevent heart block with percutaneous aortic valve replacement

ABSTRACT

Devices, systems and methods to position a prosthetic heart valve such that the prosthetic valve does not compress conduction tissue and thereby produce heart block. Guide devices promote positioning the prosthetic valve within a native aortic valve to avoid the conduction tissue and, optionally, to center the prosthetic valve within the native heart valve. Prosthetic valves include one or more cut-outs, openings or recesses configured to align with the conduction tissue so that the conduction tissue is not contacted in a way that would lead to higher incidents of complete heart block.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT Application Serial No.PCT/US2017/045070, filed Aug. 2, 2017 (pending), which relates to andclaims the priority of U.S. Provisional Patent Application Ser. No.62/467,394 filed Mar. 6, 2017 (pending); U.S. Provisional PatentApplication Ser. No. 62/445,446, filed Jan. 12, 2017 (expired); U.S.Provisional Patent Application Ser. No. 62/445,420, filed Jan. 12, 2017(expired); U.S. Provisional Patent Application Ser. No. 62/411,153,filed Oct. 21, 2016 (expired); U.S. Provisional Patent Application Ser.No. 62/381,885, filed Aug. 31, 2016 (expired); and U.S. ProvisionalPatent Application Ser. No. 62/370,435, filed on Aug. 3, 2016 (expired),the disclosures of which are incorporated by reference herein in theirentirety.

BACKGROUND

Aortic valve replacement has changed considerably in the last decade.Previously, valve replacement required a major procedure withcardiopulmonary bypass, stopping of the heart, excision of the diseasedvalve and then suture implantation of a valve prosthesis at the site ofthe excised valve. The procedure was often difficult for patients andsome older patients were too ill to undergo surgery.

This all changed when it was found that the old diseased valve could beleft in place and a prosthetic valve could be implanted inside thediseased valve using a catheter procedure. There was no need forcardiopulmonary bypass, no need to stop the heart and no need to suturea valve in position. In many countries the percutaneous procedure hasbecome the most common and preferred way to treat patients.

The valve implant procedure involves using catheters to implant one of avariety of prostheses inside the old diseased valve. In general, theprosthetic valves use leaflets fashioned from tissue taken from pigs orcows. The leaflets sit inside mounting structures or frames. Commonstructures to support the leaflets include stents (self-expanding typestents such as used by Medtronic, balloon expanding stents such as usedby Edwards, and a number of other companies), activatable frames (Sadra,Boston Scientific) and even inflatable frames (Direct Flow). To implantthese devices, the leaflets are mounted on a frame, collapsed incatheters and then introduced inside the aorta of the patient. Thevalves are positioned inside the diseased native leaflets and thendeployed and expanded to replace the function of the native aorticvalve.

Development of this procedure has been complex and is a remarkabletribute to the doctors, engineers and companies who have overcome somany obstacles. There is one particularly vexing problem that stillremains. A considerable number of patients develop complete heart blockafter the procedure. Complete heart block can occur immediately or itcan be delayed days or weeks. The atrium sets the rate of contractionfor the normal heart. The rate signal that originates in the atriumpasses into the ventricles through specialized muscular conduction orconductive tissue at the top of the interventricular septum—just a shortdistance below the aortic valve. From the top of the septum, the signalpasses to both ventricles and the ventricles contract and eject blood tothe circulation. If the conduction tissue at the top of the ventricularseptum is damaged, the signal does not pass and the ventricles do notreceive the signal to contract. This condition is called heart block orcomplete heart block. The patient's heart may then stop completely, orit may contract at a very slow rate that is not consistent withsurvival. The patient may die suddenly or become very ill. This eventcan happen unexpectedly and there is a lingering risk for development ofheart block for a prolonged period after percutaneous valveimplantation.

Heart block has been seen with all of the prostheses used to date. Itappears that the frame for the valve impacts against the conductiontissue and after a variable period of time damages the tissue and thetissue ceases to conduct the signal to contract to the ventricles. Heartblock then occurs.

Heart block can result in sudden death or a hemodynamic crisis. The riskof heart block requires prolonged monitoring because of theunpredictable nature of the event. The treatment for heart block isimplantation of a pacemaker. While this is a common and quite benignprocedure, the effectiveness of the heart's contraction with a pacemakernever reproduces the contraction that results from a healthy nativeconduction system. And pacemakers are expensive and require lifelongsurveillance necessitating visits by the patients to ensure their deviceis functioning properly and that the battery is still effective.

The rate of heart block that has been observed ranges from about 10% toas high as 30%. Despite the fact that almost a decade of work has beenconducted, no valve and no procedure to date has been shown to eliminatethe problem.

Considerable research has been conducted to understand this problem.Recently, interventional cardiologists have found that if the frame ofthe prosthetic valve sits less than 4 mm to 5 mm below the lowest pointof the native valve, heart block almost never occurs. If the prosthesissits lower than this the risk of heart block rises.

This makes good anatomic sense. Just beneath the aortic valve sits themembranous septum. The septum is a small region of non-muscular tissuethat separates the two ventricles. It sits on the top of theinterventricular septum. The conduction system that passes the signal tocontract into the ventricle sits on the crest of the interventricularseptum. The distance from the nadir of the aortic valve leaflets to theconduction tissue is approximately 4 mm. This corresponds exactly withthe clinical observation by the interventional cardiologists.

The current trend is to make every effort possible to implant aprosthetic valve to ensure that its lowest point is positioned less than4 mm below the nadir of the native aortic valve leaflets. This is noeasy feat since the valves are introduced on long catheters passing froman entry point in the groin, up the aorta, around the aortic arch andthen into the ventricle. The heart is beating and ejecting blood, andthis makes accurate positioning difficult as well. It is extremelydifficult to be sure that a valve will be deployed in the perfectposition. The person performing the procedure is also concerned that ifthe valve sits too high, it may not engage inside the native leafletsand it may be ejected out of the correct position into the aorta.

It would be very useful to have devices, systems and methods to help theinterventionist to place a prosthetic valve in the ideal position and/orotherwise reliably prevent damage to the conductive tissue. A goalshould be to prevent force from being applied to the conductive tissueafter implantation. And the prosthetic valve must not sit so high thatit does not engage securely against the native leaflets and eject out ofthe correct position.

SUMMARY

In a first general embodiment, the invention provides a prostheticaortic valve for mounting at an implant site associated with the nativeaortic valve of a patient. The prosthetic aortic valve comprises a stentframe formed from wire. The stent frame includes an upper margin oredge, a lower margin or edge, and an interior. The stent frame includesonly a single cut-out, opening or recess along the lower margin or edgeconfigured to align with conduction tissue below the native aortic valveto prevent contact by any structural element of the stent frame with theconduction tissue. The prosthetic aortic valve further includes aplurality of prosthetic valve leaflets mounted within the interior ofthe stent frame to provide unidirectional flow of blood through theprosthetic aortic valve. The provision of only a single cut-out, openingor recess helps maximize the amount of material of the prosthetic aorticvalve that assists with sealing against native heart tissue, whileproviding for no engagement or contact between any structural element ofthe stent frame with the conduction tissue that would otherwise promotethe undesired condition of heart block. This provides the dual benefitof adequate sealing, while preventing disruption of signals that couldlead to complete heart block.

The cut-out, opening or recess may be generally U-shaped, V-shaped orgenerally square shaped, although other configurations or shapes arepossible as well, such as circular or other rounded shapes. The cut-out,opening or recess could further comprise an indentation in the stentframe so that the frame avoids compression and contact with theconduction tissue at the location of the indentation. The prostheticvalve may further comprise a covering material, such as a fabric or meshmaterial, or other type of material, attached over the cut-out, openingor recess. One or more radiopaque markers may be placed adjacentopposite edges of the cut-out, opening or recess to aid in the correctorientation of the valve during implantation in relationship to theconduction tissue, i.e., for avoiding any negative contact or engagementwith the conduction tissue that might lead to complete heart block. Forexample, the marker(s) may comprise a continuous marker outlining thecut-out, opening or recess, or discrete markers on opposite sides of thecut-out, opening or recess.

In another general embodiment, the invention provides a prostheticaortic valve for mounting at an implant site associated with the nativeaortic valve of a patient, comprising a stent frame formed from wire.The stent frame includes an upper margin or edge, a lower margin oredge, and an interior. The stent frame includes a plurality of spacedapart cut-outs, openings or recesses located along the lower margin oredge. One of the cut-outs, openings or recesses may be aligned with theconduction tissue located below the native aortic valve annulus toprevent contact by any structural element of the stent frame with theconduction tissue. Prosthetic valve leaflets are mounted within theinterior of the stent frame to provide unidirectional flow of bloodthrough the prosthetic aortic valve. A covering material is fixed on theoutside surface of the stent frame to enclose the interior, but thecovering material includes a plurality of cut-outs respectively alignedwith the plurality of cut-outs, openings or recesses in the stent frame.In this manner, one of the cut-outs in the covering material aredesigned to align with the conduction tissue depending on the rotationalorientation of the prosthetic aortic valve when implanted, and the lackof contact between the covering material and the conduction tissue willfurther minimize the occurrences or chances of complete heart block.

In another embodiment or aspect of the invention, a method of implantinga prosthetic aortic valve is provided, with the prosthetic aortic valvetaking on a construction such as one of the constructions describedherein. The method generally comprises inserting the prosthetic valveinto a native aortic valve, and aligning a cut-out, opening or recess inthe prosthetic valve with the conduction tissue located below the nativeaortic annulus. The method may further comprise placing the prostheticvalve, in a collapsed condition, into a delivery sheath in a femoralartery of the patient and the prosthetic aortic valve in a predeterminedrotational orientation for ensuring that the cut-out, opening or recessis at least substantially aligned with the conduction tissue at thenative aortic valve. The method may further comprise using at least oneradiopaque marker placed on the prosthetic aortic valve adjacentopposite edges of the cut-out, opening or recesstor align the cut-out,opening or recess with the conduction tissue.

In another embodiment of the invention, a system is provided to assistpercutaneous aortic valve replacement. The system generally comprises aprosthetic aortic valve movable between a collapsed condition suitablefor percutaneous delivery into a native aortic valve and an expandedcondition within the native aortic valve. The system further includes aguide device configured to engage native heart tissue and guiding valvedeployment and expansion away from the conduction tissue of the heart.The system may further involve integrating the guide device with theprosthetic aortic valve. In another aspect, the guide device iscomprised of wire and takes on the form of at least one of: a helix, abasket, and a plurality of radiating arms.

In another embodiment or aspect, the invention provides a method ofimplanting a prosthetic aortic valve, comprising using a guide device toidentify the nadir of the aortic valve leaflets or the left ventricularoutflow tissue, and percutaneously implanting a prosthetic aortic valvehaving a valve frame so that no portion of the valve frame contactsconduction tissue located below the native aortic annulus. The methodmay further comprise removing the guide device from the patient througha catheter after implanting the prosthetic aortic valve, and avoidingtrapping the guide device with the expanding prosthetic valve. Themethod may also or alternatively comprise using at least one radiopaquemarker on the guide device and the prosthetic aortic valve to locate theprosthetic aortic valve relative to the guide device at the nativeaortic valve. The method may additionally involve using the guidedevice, or a separate centering guide, to center the placement of theprosthetic aortic valve within the native aortic valve duringimplantation.

Various other embodiments, aspects, features and attendant advantageswill become apparent upon review of the following more detaileddescription of the illustrative versions of devices, systems and methodsconstructed consistent with the inventive concepts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an inflatable prostheticaortic valve being inserted into a native aortic valve in accordancewith a prior art method.

FIG. 2 is a perspective view, partially cross sectioned and schematicillustrating the prosthetic valve of FIG. 1 implanted and engagingconduction tissue in a manner that may promote heart block.

FIG. 3A is a perspective view, partially cross sectioned and schematicillustrating a guide device used in conjunction with the system andprosthetic valve shown in FIGS. 1 and 2 for preventing engagementbetween the prosthetic valve and the conduction tissue.

FIG. 3B is an illustration similar to FIG. 3A, but illustrating theprosthetic valve implanted at the native aortic valve with the guidedevice, e.g., guide balloon also in place.

FIGS. 3C and 3D are respective illustrations similar to FIG. 3B, butillustrating further inflation of the inflatable valve and theinflatable balloon guide device.

FIG. 3E is an illustration similar to FIG. 3D, but showing the fullyimplanted inflatable valve prosthesis out of engagement with theconduction tissue.

FIG. 3F is a perspective view illustrating the inflatable valveprosthesis and inflatable guide device in isolation from the anatomy.

FIG. 4A is a schematic view with the anatomy again cross sectioned toillustrate the implantation of a self-expanding stent valve, inconjunction with another embodiment of a guide device for ensuring thatthe stent valve does not engage or contact the conduction tissue in anegative manner.

FIG. 4B is an illustration similar to FIG. 4A, but illustrating afurther point in the method during which the self-expanding stent valveand its delivery system are inserted through the native aortic valve.

FIG. 4C is a schematic cross sectional view illustrating the fullyimplanted self-expanding stent valve, again out of negative contact orengagement with the conduction tissue.

FIG. 5A is an illustration similar to FIG. 4A, but illustrating anotheralternative, or additional embodiment of a locating or guide devicepositioned in the left ventricle.

FIG. 5B is an illustration similar to FIG. 5A, but illustrating afurther point in the method during which the delivery system andunexpanded stent valve are inserted through the native aortic valve andthe guide device is drawn against an underside of the native aorticvalve.

FIG. 5C is an illustration similar to FIG. 5B, but illustrating theprosthetic stent valve expanded, and with the guide device still inplace.

FIG. 5D is an illustration similar to FIG. 5C, but illustrating theguide device removed.

FIG. 6 is an illustration showing the anatomy cross sectioned, and theinsertion of an expandable stent valve, using a guide device above thenative aortic valve.

FIG. 7A is an illustration with the anatomy cross sectioned and showingthe insertion of an expandable stent valve through the native aorticvalve and a guide device within the left ventricle.

FIG. 7B is an illustration similar to FIG. 7A, but further illustratingan inflatable device being used to move the guide device out of positionas the prosthetic stent valve is expanded.

FIG. 7C is an illustration similar to FIG. 7B, but illustrating afurther point in the process during which the stent valve is fullyexpanded by the balloon device, and other portions of the balloon deviceare moving the guide device out of the way.

FIG. 7D is an illustration similar to FIG. 7, but illustrating the fullyimplanted expandable stent valve.

FIG. 7E is an enlarged cross sectional view illustrating the balloondevice and guide device of FIG. 7C.

FIG. 8A is an illustration of the cross sectioned heart anatomy and theintroduction of an expandable prosthetic stent valve into the aorticimplant location, with a helical positioning guide device located in theleft ventricle.

FIG. 8B is an illustration similar to FIG. 8A, but showing a furtherpoint in the method during which the expandable stent valve is locatedwithin the native aortic valve and the positioning guide device is drawnup against the underside of the native aortic valve.

FIG. 8C is an illustration similar to FIG. 8B, but showing a furtherpoint in the method during which the guide device is moved out of theway by expandable balloon elements as the stent valve is expanded.

FIG. 8D is an illustration similar to FIG. 8C, but showing a furtherpoint in the process during which the guide device has been moved out ofthe way and the prosthetic stent valve has been more fully expandedagainst the leaflets of the native aortic valve.

FIG. 9A is an illustration of another embodiment showing the insertionof an expandable stent valve into the implant location of the nativeaortic valve, and a positioning guide device located in the leftventricle.

FIG. 9B is an illustration similar to FIG. 9A, but further showing apoint in the process during which the stent valve has been inserted intothe native aortic valve.

FIGS. 10A through 10C are similar views to the methodology shown inFIGS. 9A and 9B, more specifically showing the progression of valveexpansion and movement of the guide device out of the way withadditional balloon elements or portions.

FIG. 10D is a view similar to FIG. 100, but illustrating full expansionof the prosthetic stent valve and movement of the guide device out ofthe way such that it not trapped between the stent valve and nativetissue.

FIGS. 11A through 11D illustrate another embodiment in which both aheight or level guide device and a centering device are used to positiona stent valve during insertion and expansion of the valve.

FIGS. 12A through 12C illustrate another embodiment of a guide deviceand the progressive methodology used for inserting and expanding aprosthetic aortic valve while using the guide device to locate the stentvalve away from the conduction tissue.

FIGS. 13A through 13C illustrate the progression of a method for usinganother alternative embodiment of a guide device for positioning a stentvalve within the native aortic valve and away from the conductiontissue, while simultaneously moving the guide device out of the wayduring the implantation process.

FIGS. 14A through 14C respectively illustrate another embodiment of theinvention in the form of an integrated guide device and guide wire usedfor locating and implanting a prosthetic heart valve.

FIGS. 15 and 16 respectively show the anatomy of a native aortic valveand surrounding anatomical structure in a schematic form.

FIG. 17 schematically illustrates the plane of a native aortic valve andimaging process for use during an aortic valve prosthesis implantation.

FIGS. 18A through 18C illustrate a method of inserting an expandableprosthetic stent valve into the native aortic valve and implanting theprosthetic valve in accordance with a prior art method.

FIGS. 19A and 19B illustrate respective embodiments of an expandablestent valve having a cut-out, opening or recess for alignment with anavoidance of the conduction tissue within the heart.

FIG. 19C is an elevational view similar to FIGS. 19A and 19B, butillustrating an expandable stent valve with a cut-out recess or openingfor avoiding the coronary arteries.

FIG. 19D is an illustration similar to FIG. 19A, but illustrating theopening covered with a mesh material for creating a mesh covered recess.

FIG. 20 is a cross sectional view taken along line 20-20 of FIG. 19, andillustrating the prosthetic stent valve schematically placed at thelocation of the native aortic valve with the mesh covered recess inalignment with the conduction tissue.

FIG. 21 is a schematic view illustrating another embodiment of a stentvalve having an opening, recess or cut-out in alignment with theconduction tissue.

FIG. 22 is a perspective view illustrating another embodiment of a valveprosthesis including a mesh covered recess or opening for avoidance ofany engagement with the conduction tissue.

FIG. 23A is a schematic illustration of another embodiment of anexpandable valve prosthesis at the location of the native aortic valvehaving a cut-out or opening in alignment with the conduction tissue.

FIG. 23B is a view of the stent valve shown in FIG. 23A, butillustrating a fabric covering and three respective openings or cut-outsalong the lower margin or edge of the stent valve.

FIGS. 24A and 24B are views similar to FIGS. 23A and 23B, butrespectively illustrating an alternative embodiment of an expandablestent valve having cut-outs or openings at the lower margin or edge.

FIGS. 25A and 25B are respective views of a prosthetic stent valveincluding openings or cut-outs for avoiding the conduction tissue.

FIG. 26A is a schematic view of another embodiment showing an expandablestent valve with cut-outs and flared tabs or flanges between thecut-outs.

FIGS. 26B and 26C show respective alternative embodiments of anexpandable prosthetic stent valve in a flattened or opened condition forclarity, and illustrating additional embodiments of tabs or flangesseparated by respective cut-outs or gaps, in which the tabs or flangesmay be used to better fix the stent valve in place within the heart, andone of the gaps may be aligned with the conduction tissue.

FIG. 27 is a schematic view, showing the heart anatomy in cross section,and with the stent valve of FIGS. 26A and 26B implanted.

FIG. 28A-1 is a photographic image of a native aortic valve.

FIG. 28A-2 is a drawing of the image shown in FIG. 28A-1.

FIG. 28B is an illustration similar to FIG. 28A-2, but illustrating dyeinjected into the aorta and other anatomy.

FIG. 28C is a schematic illustration showing the expandable stent valveof FIG. 27 being inserted into the native aortic valve.

FIG. 28D is an illustration of the prosthetic stent valve shown in FIGS.27 and 28C fully implanted at the site of the native aortic valve.

FIG. 29A is a perspective view of a prosthetic, expandable stent valvesimilar to the valve shown in FIG. 28D and including a fabric or othertype of covering.

FIG. 29B is an elevational view of the valve shown in FIG. 29A, but withthe covering removed.

FIG. 29C is a top view of the prosthetic valve shown in FIG. 29A.

FIG. 30A is a top view of the native aortic anatomy.

FIG. 30B is a top view schematically illustrating the valve of FIG. 29Cinserted into the anatomy shown in FIG. 30A.

FIGS. 31A-1 and 31A-2 are respective views similar to those of FIGS.28A-1 and 28A-2.

FIG. 31B-1 is a photographic image showing the native aortic valve andaorta from an angle illustrating the non and right coronary cusps.

FIG. 31B-2 is a drawing illustrating the features shown in the image ofFIG. 31B-1.

FIG. 31C is a schematic illustration showing the insertion and initialimplantation of an expandable stent valve in accordance with anembodiment of the invention being inserted into the native aortic valve.

FIG. 31D is an illustration similar to FIG. 31C, but illustrating thefully implanted expandable stent valve within the native aortic valve.

FIG. 32A is an illustration similar to FIG. 31C, but illustrating theuse of a positioning or guide device within the left ventricle duringthe implantation procedure.

FIGS. 32B and 32C are illustrations similar to FIG. 32A, but showing analternative guide device being used for positioning the expandable stentvalve at a level that avoids contact or negative engagement with theconduction tissue.

FIG. 33A-1 is a photographic image illustrating the native aortic valveand adjacent anatomy or components.

FIG. 33A-2 is a drawing illustrating the features shown in thephotographic image of FIG. 33A-1, and illustrating the initialimplantation of an expandable stent valve within the native aorticvalve.

FIG. 33B is an illustration similar to FIG. 33A-2, but illustrating afurther point in the procedure during which the expandable stent valvehas been inserted through the native aortic valve.

FIG. 33C is a view similar to FIG. 33B, but illustrating expansion ofthe stent valve within the native aortic valve.

FIG. 33D is a view similar to FIG. 33C, but illustrating full expansionand implantation of the prosthetic stent valve within the native aorticvalve.

FIG. 34 is a diagram illustrating the angle of a typical native aorticvalve and optimal viewing image location for a procedure conducted inaccordance with the embodiments of the invention.

FIG. 35 is a schematic illustration of a patient and the entry locationand orientation procedure associated with embodiments of the invention.

FIG. 35A is an enlarged view of the insertion location and orientationprocedure for an expandable stent valve in accordance with embodimentsof the invention.

FIG. 36A is a schematic illustration of an inflatable prosthetic aorticvalve constructed in accordance with an embodiment of the inventionbeing inserted into a native aortic valve.

FIG. 36B is a view similar to FIG. 36A, but illustrating full expansionand implantation of the inflatable prosthetic valve within the nativeaortic valve.

DETAILED DESCRIPTION

In this description, like reference numerals refer to like structure.Such structure may having different forms, as will be apparent from thedescription and/or drawings, but the same or analogous function. Inlater figures, description of repetitious subject matter or elementswith the same reference numbers as earlier described is avoided forconciseness. Any of the features, uses, components or other aspects ofan embodiment may be combined with any other embodiment.

FIG. 1 shows the implant of a percutaneous, prosthetic aortic valve 10of the prior art that is supported by an inflatable frame 12. The figureshows a diseased native aortic valve 14 with stiff and thickenedleaflets 16, 18. The aorta 20 sits above the valve 14. Below the valve14 is the inside of the left ventricle 22. Beneath the valve 14 one sidethe anterior leaflet 16 of the aortic valve 14 is shown. On the otherside is the interventricular septum 24. The conduction tissue 30 isidentified by a small region located just below the valve leaflets 16,18. The conduction tissue 30 sits on the crest of the muscularinterventricular septum 24. The tissue above the conduction tissue 30 isthe membranous septum 31. This is not muscular tissue.

The inflatable prosthetic valve 10 is introduced into the circulation ina collapsed state through introducers often at the groin of the patient.The collapsed valve and its delivery system are then passed up theaorta, through the disease aortic valve 14 and into the left ventricle22. The valve 10 is then partially inflated for full deployment. It isparticularly useful to inflate the upper circular element 32 of thesupport frame less and the lower element 34 of the support frame more asshown in this figure. This arrangement allows the interventionist topull the valve prosthesis 10 inside the diseased leaflets 16, 18. Thearrow 36 indicates the planned direction of pull.

Small narrow catheters 38, 39 are shown that are attached to theinflatable frame of the prosthesis 10 to inject fluids to inflate andexpand the support structures.

As shown in FIG. 2, the valve 10 has been pulled up into its finalposition. The lower element 34 of the valve frame, being inflated more,acts as a “stopper” and positions the valve 10 inside the diseasednative leaflets 16, 18. The upper element 32 and the rest of the frameis then fully inflated.

FIG. 2 also shows why heart block is common. The lowest circular framesupport 34 impinges against the conduction tissue 30 (shown by theirregular lines surrounding the conduction tissue 30). After anunpredictable period of time the conduction tissue 30 becomes damagedand it ceases to conduct the signal to contract. Heart block thenresults.

FIG. 3A illustrates a device, system and method in accordance with anexemplary embodiment of the invention to avoid the development of heartblock. The same inflatable prosthesis 10 is shown as in the prior twofigures. What is added is an additional item, i.e., an inflatableballoon guide or locator device 40. Although this guide or locatordevice 40 is an inflatable device, it will be understood that this isjust an illustrative example and other types of locator devices may beused instead. For example, as will be further illustrated and discussedherein, various mechanical locator devices may be utilized instead. Inthis example, the locator device or guide 40 is an additional balloonthat sits under the prosthesis 10. It is used only during the implantprocedure and is removed or otherwise deactivated after the procedure soas not to negatively affect the heart. The inflatable balloon guide 40has a separate inflation catheter 42 shown in the figure. The ballooncan be inflated with air or fluid (with or without contrast material toidentify it on fluoroscopy). The balloon 40 can be constructed from anytypical plastic material that is used for medical devices. It can alsohave radiopaque markers to help visualize it on fluoroscopy.

The implant procedure is similar to what has been described previously.The inflatable frame for the valve is directed into the left ventricle22 and then partially expanded. The guiding balloon 40 is expanded. Theballoon guide 40 is linked to the valve prosthesis 10.

The balloon guide 40 is pulled back until it engages against the undersurface of the left ventricle 22 (the left ventricular surface) of thelowest point of the diseased native aortic valve leaflets 16, 18 (thenadir of the leaflets 16, 18). The leaflets 16, 18 are typicallysclerotic and often calcified and will reliably produce a resistancewhen the balloon guide 40 is pulled back toward the leaflets 16, 18.

As shown in FIG. 3B, the balloon guide 40 has been pulled upwards towardthe diseased valve 14 until it stops under the diseased valve leaflets16, 18. The balloon guide 40 will be engaged by the leaflets 16, 18.

The left ventricular outflow narrows under the aortic valve 14. Theballoon guide 40 can also be engaged against the left ventricularoutflow.

A sounding device (i.e., the locator device or guide) 40 could alsoengage against both the narrowing left ventricular outflow and theunderside of the leaflets 16, 18.

The inflatable valve prosthesis 10 is now ready to be expanded. Thediseased aortic valve leaflets 16, 18 are pushed aside and they engageagainst the frame of the prosthesis 10 to hold it in place.

FIG. 3B shows that the prosthesis 10 now sits at a slightly higherposition than in the previous figures (FIGS. 1 and 2) where the balloonguide 40 was not used.

The lowest circular frame element 34 sits well above the conductiontissue 30.

After the implant, the balloon guide 40 is deflated and removed. Onlythe valve prosthesis 10 is left in place.

FIG. 3B schematically indicates that the conduction tissue 30 isapproximately 4 mm below the native leaflets 16, 18, as shown bydistance “d”.

FIG. 3C shows the prosthesis 10 with attached inflation catheters 38, 39sitting in an ideal position well above the conduction tissue 30.

An arrow 46 shows the lowest element 34 of the frame being inflated andexpanded inside the diseased leaflets 16, 18.

FIG. 3D shows the upper element 32 and the vertical support members 48of the prosthesis 10 being expanded. Arrows 50 on the inflationcatheters 38, 39, 42 show the direction of flow of the filling material.

Additional arrows 52 show the prosthetic valve 10 expanding into thediseased native leaflets 16, 18.

FIG. 3E shows the final implant location. Both the upper and lowercircular supports 32, 34 as well as the vertical supports 48 areexpanded. The balloon guide 40 has been removed. The valve 10 does notcontact the conduction tissue 30.

FIG. 3F shows the temporary guide balloon 40 with the valve prosthesis10. In this figure the temporary guiding balloon 40 is very close ortouching the lowest circular inflatable member 34. There could also be agap between the temporary inflatable balloon 40 and the valve prosthesis10. It is also possible to have an overlap between any adjacentballoons. These constructions will help establish the ideal finalposition (higher or lower) of the prosthesis 10 inside the native aorticvalve 14.

The inflatable guide 40 is shown here as a “doughnut” shaped structure.It could be a sphere or disc, but this would block the ejection of theblood out of the left ventricle 22. Any balloon guide shape that allowsthe guide to set a reliable position relative to the aortic valveleaflets 16, 18 and left ventricular outflow path can be used. Forexample, a cylinder or a tapered cylinder could be used. The cylinderwould allow blood to flow through the native aortic valve 14 during theprocedure.

These figures have shown a temporary guide 40 that is used to find theideal position for the valve 10 and that is removed at the end of theprocedure. It is also possible to integrate this delivery concept withthe prosthesis design. For example, there could be two lower circularsupport rings in the valve prosthesis 10. The lowest one could beinflated to guide the position of the valve 10. The circular ring orelement just above the lowest ring could then be inflated inside thediseased valve 14. The lowest ring could be deflated partially orcompletely so that it does not contact conducting tissue 30. Although itseems more reasonable at this time to have a temporary and separateballoon guide, it may prove easier to construct the devices or implantthe devices in an integrated format.

FIG. 4A shows a self-expanding aortic prosthesis 60 compressed inside asheath or catheter 62. The prosthesis 60 is located in the aorta 20 andready to be passed into the correct position inside the diseased andthickened leaflets 16, 18 for deployment.

A different guiding or locator device 70 is shown here. There is acatheter 72 passing into the left ventricle 22. The catheter 72 has aguide wire 74 in it passing toward the apex of the left ventricle 22.

Also passing through the catheter 72 is the locating or guiding device70. This device 70 is not a balloon. A series of curved arms 70 a, 70 bare straightened and passed through the catheter 72 into the leftventricle 22. Once inside the left ventricle 22, the arms 70 a, 70 bspring into their preformed curved shape. The arms 70 a, 70 b of thesounding or guiding device 70 are then pulled back until it engagesagainst the underside of the diseased aortic leaflets 16, 18. Theoperator will feel the arms 70 a, 70 b pulling against the leaflets 16,18 and know that the tips of the arms 70 a, 70 b are now just underneaththe aortic leaflets 16, 18. Also, using fluoroscopy, the operator willbe able to see the arms 70 a, 70 b begin to buckle or bend as they areengaged under the leaflets 16, 18.

The sounding or locator device 70 could be made with shape memorymaterial such as Nitinol so that it can be straightened for insertionand then assume its functioning shape. As Nitinol is sometime hard tosee on fluoroscopy, radiopaque markers (such as gold), could be added.Or the Nitinol could be mixed with a radiopaque material for easyidentification on fluoroscopy during the procedure.

As shown in FIG. 4B, the sheath 62 holding the self-expanding stentvalve 60 inside is advanced so that its tip is in the left ventricle 22and the end of the catheter 62 is “stopped” in the correct position bythe sounding or guiding device 70. As explained, the stop point can beidentified by tactile feedback and visually from fluoscopy or otherimage guidance.

It is important to note that the guiding or locator device 70 is keepingthe implant of the prosthesis 60 away from the conduction tissue 30. Itwill identify the lowest safe location that the interventionist canrelease the implant 70 once the system is fully implanted.

The relative positions of the catheter 62 that delivers the valve 60 andthe guiding device 70 could be fixed by the manufacturer. The stent of aprosthetic valve 60 is lengthened when it is loaded inside the catheter62. The prosthetic valve 60 shortens as the sheath 62 is withdrawn. Acareful study of the amount of shortening would be necessary to set thedistance between the “stop” point on the guide or sounding device 70 andthe end of the sheath 62 that contains the valve prosthesis 60 to ensurethe valve 60 deploys correctly.

FIG. 4C shows the implanted device 60. The retaining sheath 62 has beenfully removed. The prosthetic valve 60 is fully deployed and engagedagainst the diseased native leaflets 16, 18.

Most importantly, the small circle of conduction tissue 30 at the top ofthe septum 24 is not contacted by the frame of the valve 60. A distance“d” separates the lowest part of the stent 60 from the conduction tissue30.

FIG. 5A shows another type of prosthesis 80 being delivered. Thisprosthesis 80 is a balloon expandable stented valve. The stent valve 80is typically made from stainless steel alloys.

The prosthesis 80 has been introduced into the aorta 20 and is about tobe guided into position inside the diseased leaflets 16, 18.

Inside the left ventricle 22 is a guide wire 82 which is passed towardthe apex of the ventricle 22.

There is also another variation of a locator or sounding device 90. Thisdevice 90 is shown as a helical wire. The wire 90 can typically becomposed of Nitinol. The Nitinol can be straightened for delivery insidea catheter 96 that may also carry the guide wire 82. The helix 90 willform inside the ventricle 22 as the Nitinol locator device 90 isextruded out of the catheter 96. The turns or coils of the helix 90 canbe fabricated with a gap. A larger or smaller gap may be desirable in aclinical procedure.

In FIG. 5B, the helical locator or sounding device 90 has been pulledback against the underside of the diseased aortic valve leaflets 16, 18.

The interventionist can feel the tension that will result. Also, theturns of the helix 90 will compress against each other so there will bea visual clue that the desired position under the leaflets 16, 18 of thevalve 14 has been reached. As explained previously, the use ofradiopaque markers may be useful on the helical guide or locatorstructure 90.

After the helical guide 90 has been pulled into position, the prostheticvalve 80 is pushed forward. The guide 90 and the prosthesis 80 can beconstructed to ensure that the final position of the implanted valve 80(after the stent valve 80 has been expanded and the stent valve 80 hasshortened), is above the conduction tissue 30 but still securely insidethe native leaflets 16, 18.

The relation between the position of the prosthesis 80 and the guidingdevice 90 can be fixed by placing stoppers on the guiding device 90. Theoperator can also move the prosthesis 80 so that there is the correctspacing between the guiding device 90 and the prosthesis 80. Apre-determined gap could be defined in millimeters from the upper turnor coil of the helix 90 and the position of the valve delivery system orcatheter 62.

In FIG. 5C, a balloon 100 (FIGS. 5A, 5B) has been inflated and removed.The valve prosthesis 80 is expanded inside the diseased native aorticvalve leaflets 16, 18.

The valve 80 sits safely above the conduction tissue 30 that is at thetop of the muscular septum 24. There is no risk of injury to theconduction tissue 30 by any structure of the stent valve 80.

The helical guiding or sounding device 90 is still in position.

As described above, it may be useful to add radiopaque markers (notshown) to the sounding or guiding devices, such as device 90. Themarkers could also be added to the balloon inflatable guidingstructures, previously shown.

Clinicians may also find it useful to add EKG electrodes to the guidingor sounding devices. The membranous septum 32 above the conductiontissue 30 is not muscular. So an electrode contacting the membranousseptum 31 will not show EKG activity. The addition of EKG detection toany of the sounding devices may precisely identify the location of theseptal muscle 24 and membranous septum 32 for further improved guidanceof the procedure.

It should also be noted that pre-procedure imaging is performed verycommonly using CT, MR and Echo. Information derived from these studiescould be used to determine the location of the membranous septum 32, thelocation of the lowest part of the aortic valve leaflets 16, 18, thediameter of the left ventricular outflow and the gap between the top ofthe muscular septum 24 (where the conduction tissue 30 reliably sits)and the native leaflets 16, 18. These measurements could help select aguide device that will impact in the left ventricular outflow at a pointbelow the leaflets 16, 18. Or it could help to determine where todeliver a valve prosthesis relative to a marker on the guiding orsounding device.

These figures have shown a variety of guiding or sounding devices toidentify the undersurface of the aortic leaflets 16, 18 or the leftventricular outflow. Inflatable and non-inflatable guide devices havebeen shown. These examples of position locating guides or soundingdevices is not exhaustive but intended to show examples of the conceptof using a locating device to guide an aortic prosthesis implant into aposition that avoids negative contact with conductive tissue 30.

In FIG. 5D, the delivery system and guiding device has been removed.Only the prosthetic valve 80 remains. The valve stent 80 sits well abovethe conduction tissue 30. Heart block should not occur in thissituation.

These figures have shown frames that are made from stents(self-expanding and balloon expanding) and inflatable frames. Otherprosthetic valves are being used such as the Boston Scientific Sadravalve that has an adjustable frame. Any aortic valve implant orprosthesis could be combined with the position guiding or soundingconcepts, methods and devices described in this disclosure.

The previous figures have all used the reference of the under surface ofthe aortic valve leaflets 16, 18 or the narrowing of the leftventricular outflow to position a sounding or locator device. It is alsopossible to use the upper surface of the aortic leaflets 16, 18 toobtain an internal reference point to guide implantation of a prostheticvalve.

FIG. 6 shows an inflatable sounding or locating device 110 that isshaped like a doughnut. It is pushed forward until it stops inside theaorta 20 on the tops of the cusps of the aortic valve leaflets 16, 18. Avalve prosthesis 120 is advanced relative to the position of thesounding (guide or locator) device 110. The ideal relative positions ofthe guide 110 and the correct location for deployment of the prosthesis120 could be determined using pre-operative measurements from imagingthat could reliably generate measurements from the tops of the cusps tothe conduction tissue 30. The guide device 110 does not need to beinflatable. Guide devices such as those shown previously (like a helixor multi-armed anchor) could be used.

It appears to make most sense to use the underside of the valve 14 orthe outflow of the left ventricle 22 for the guide (such as previouslydescribed) because this is so close to the location of the conductiontissue 30 and there should be less error in using this as a reference.However, clinical practice and in product development, the use of theupper plane of reference may show advantage.

Also, it may be useful to use guidance or sounding devices both belowthe native valve 14 and above the native valve 14. The operator couldthen visually or by the use of stoppers determine where to locate theposition to deploy the prosthetic valve 120.

The disclosure above describes how a sounding or locating device can beused to help position a percutaneous valve for aortic valve replacement.Specifically, it has been found that the risk of heart block isincreased when the valve prosthesis sits lower than 4 to 5 mm from thebottom of the native aortic valve 14. This is not surprising since theconduction tissue 30 that transmits the signal to the ventricles passesin this region and it is likely that the valve frame causes damage tothe conduction tissue. The devices, method and systems describedpreviously show how heart block can be avoided.

Disclosure below focuses on how the sounding or locating device can beplaced to aid in ideal placement of the valve, and then moved during theprocedure so that the locating device does not become trapped by theframe of the prosthetic valve. This allows the locating device to beeasily removed at the end of the procedure.

The disclosure below also focuses on how the sounding or locating/guidedevice can be used to center the valve prosthesis during implantation.The prosthetic valve is generally inserted on catheters that travelaround the curve of the aorta 20. Because of the curved insertion path,the valve prosthesis naturally has a tendency to locate itself to theoutside of the curve—and not in the center of the native valve 14. Itmay be beneficial to have the valve prosthesis positioned in the centerof the aortic outflow when it is deployed.

FIG. 7A shows a prosthetic aortic valve 130 being inserted inside apatient's diseased native aortic valve 14. A guide wire 132 has beendirected into the left ventricle 22 through the valve delivery system62. A balloon expandable stent valve 130 is being moved into positioninside the diseased valve 14.

The sounding or locating device 70 is shown sitting under the aorticvalve leaflets 16, 18. The sounding device 70 has been describedpreviously. The arms 70 a, 70 b sit under the native aortic valveleaflets 16, 18. They can be positioned by “feel”—the interventionalcardiologist can feel the tension as they are pulled back against thevalve leaflets 16, 18 or this may be done visually by fluoroscopy.

The number and length and the configuration of the arms 70 a, 70 b canvary. There could be two or three or a much larger number of arms 70 a,70 b. These arms are quite long and the tips of the arms 70 a, 70 b sitaround the undersurface of the perimeter of the valve 14. The arms 70 a,70 b could have a tighter turn and sit under the body of the leaflets16, 18.

In FIG. 7B, the aortic valve prosthesis 130 has been pushed intoposition and engaged relative to the sounding or locating device 70.

The system is constructed so that when the sounding device 70 ispositioned under the native mitral valve 14, the prosthetic valve 130will be delivered in the correct position. At this time the correctposition for the final resting position of the lowest point of the valvestent 130 is thought to be no more than 4 mm from the bottom of thevalve leaflets 16, 18. The system should be constructed so that thevalve delivery system is correctly adjusted with the sounding orlocating device 70 to deliver the desired final depth of for theprosthetic valve 130 that the system is using.

It should be noted that the balloon expanded stent valve 130 iscollapsed for delivery in the catheter system. The collapsed stent 130is longer than the final length of the expanded stent 130. So the systemhas to take into account the fact that a longer balloon 100 is necessaryfor delivery and that the stent valve 130 shortens as it is expanded bythe balloon 100.

FIG. 7B shows a plurality of balloons 150 (two in this example) beinginflated against the arms 70 a, 70 b of the locating device 70. Once thelocating device 70 has been used to correctly position the valve 130,the valve 130 is ready for deployment. If the valve 130 is expandedimmediately, there is a risk that the arms will become trapped under theexpanded stent of the valve prosthesis 130. The two balloons 150 areshown being inflated prior to the inflation of the balloon 100 thatinflates the valve 130. These serve to move the locating arms 70 a, 70 baway from the path of the expanding aortic valve prosthesis 130 toguarantee they will not be trapped in position and prevent the removalof the locating device 70.

The balloons 150 can be any in number. They can be located anywhere inthe delivery system. They can be, for example, on the tip of the distaldelivery system. They can be attached to the main stent expandingballoon 100 itself. They can be out-pouches of the main balloon 100 thatinflates the valve 130.

FIG. 7C shows the locating arms 70 a, 70 b being pushed downward andaway from the annulus 14 a of the aortic valve 14. The arms are wellclear of the inflating aortic valve prosthesis 130.

There are alternative approaches to using a balloon to move the locatingor guide device out of the way during implantation of the valveprosthesis. Rods or pusher wires could be used to push the arms. Also,the operator could use the positioning device to achieve the desiredlocation for the prosthesis. The positioning device could then be moveaway by the operator. The valve prosthesis could then be deployed. Theselocating devices could also be moved away manually before the valveprosthesis is deployed to avoid the need for balloons or otherinterventions to avoid trapping the locating device behind the valve.

As shown in FIG. 7D, at the end of the procedure the locating device 70,and any other components of the delivery system are removed. Theprosthetic valve 130 is in position. Note that the conduction tissue 30is not contacted by the prosthetic valve 130. There should be no risk ofheart block in this procedure.

FIG. 7E shows a variation of a balloon 100′ that forces the arms 70 a,70 b of the locating device 70 away from the valve implantation siteduring implantation. The balloon 100′ that pushes the arms 70 a, 70 baway could be separate from and have a separate inflation channel thanthe balloon 100 that inflates to expand the stent valve 130.

A common inflation channel makes most sense from the point of view ofsimplicity of construction. The valve 130 is tightly crimped on theinflating balloon 100. When the balloon 100 is first inflated, the parts150 of a balloon 100 that pushes against the fingers or arms 70 a, 70 bwill deploy since there is much less resistance to expansion. Once thefingers or arms 70 a, 70 b are pushed away, balloon 100 or 100′ willbegin to inflate the stent valve 130.

FIGS. 8A-8D show the implantation of a balloon expandable prostheticaortic valve 130 with a helical shaped locating or sounding device 160.

As in the previous figures and as shown in FIG. 8A, a guide wire 82 andthe sounding or locating device 160 are positioned inside the leftventricle 22.

The valve prosthesis 130 is being advanced inside the patient's diseasednative aortic valve leaflets 16, 18. On the tip of the delivery systemis an inflatable component or balloon 100′ that will be used to move thelocating device 160 away from the implantation site.

In FIG. 8B, the locating device 160 has been pulled up against theunderside of the aortic leaflets 16, 18.

The valve 130 has been positioned inside the patient's diseased aorticvalve 14. The depth of the insertion of the valve 14 is guided by thesounder or locator device 160. This will ensure the correct depth of theimplantation. Conduction tissue 30 can be avoided without implanting thevalve 130 too high. Each prosthetic valve design will have to becarefully studied to ensure the positioning device results in thecorrect level of deployment.

If the balloon 100′ was now inflated to expand the aortic valveprosthesis 130, there is a risk that the helix guide device 160 would betrapped under the prosthetic valve 130.

Two arrows 164 show the path of the expansion of the inflatable pusher100′. Such inflatable balloons or elements 150 will engage against thelocating device 160 and push the device 160 away from the frame of thevalve 130 once it has served its function of correctly positioning thevalve 130.

The helical sounding or locator device 160 has a number of turns orcoils located in approximately the same plane. The helical sounding orlocator device 160 may also have turns in different planes. For example,the helix 160 could form a conical shape that is open toward the aorticvalve annulus 14 a with turns or coils that are wider closer to thenative annulus 14 a.

One particularly useful shape (not shown) may be a circular locatordevice that has a sinusoidal shaped portion moving to and away from theannulus 44 a. These sinusoidal shaped portions could also be included ina helix.

The locator or sounding device can have many useful alternative shapes.

FIG. 8C shows the valve prosthesis 130 is now in the correct position.The inflatable pusher 100′ has been expanded. The helical positioning orlocator/sounding device 160 is now pushed away from the valve 130 andthe valve 130 is now ready to be expanded into position. The path ofexpansion of the prosthetic valve stent 130 is shown with the horizontalarrows 168.

As shown in FIG. 8D, the balloon 100′ has now fully expanded the stentof the prosthetic valve 130.

The inflatable pusher 100′ moved the sounding device 160 away from theimplant site so it is not trapped by the valve 130.

The inflatable pusher elements can be of any number. They can be mountedon the distal tip of the delivery system or be associated with theballoon that expands the prosthetic valve 130 or they could be aseparate element. As explained previously, it is not necessary to useballoons to push the locating device 160. A mechanical rod could beused. Or the locating device 160 could simply be moved by theinterventionist prior to fully implanting the valve prosthesis 130.

FIG. 9A shows the implantation of a balloon expandable prosthetic aorticvalve 130 that is similar to the Edwards Sapien 3 system. The stentvalve 130 is crimped and mounted on a balloon 180 that is longer thanthe valve prosthesis 130. A sounder or locator device 70 is positionedbelow the aortic valve 14. It should be noted that the locating devicecould be a different shape. For example, the locating device 70 could beinstead formed as a helical structure. The stent valve delivery systemis being pushed over a guide wire 82 inside the diseased native aorticvalve leaflets 16, 18. The arrows 182 indicate the direction of travel.

In FIG. 9B, the valve 130 is positioned in the correct position by thelocating device 70 so that the expanded valve 130 will not contact theconducting tissue 30. The balloon 180 is expanded. The distal part 180 aof the balloon 180 expands first as no stent is crimped on it and thereis no resistance to its expansion. The expanding balloon portion 180 amoves toward the arms 70 a, 70 b of the locating device 70.

The system could also be constructed so the distal tip of the deliverysystem is moved forward to push the locating device 70 away. This couldbe activated by the balloon 180 or by a mechanical push mechanism (notshown) in the delivery system.

FIGS. 10A and 10B show cross sections of the profile of the balloon 180respectively before and after inflation. This balloon 180 expands like atube or cylinder to push the locating device 70 away from the annulus 14a.

As shown in FIG. 100, after the locating device 70 has moved away, theballoon 180 now expands the aortic valve prosthesis 130. The arrows showthe balloon expanding the stent of the valve. The arrows 186 show thevalve stent 130 moving outwards.

It is important to note that the arms 70 a, 70 b of the locating device70 are moved free of the path of the expanding aortic valve prosthesisstent 130. For this reason, the arms 70 a, 70 b will not be trapped.

FIG. 10D shows the valve 130 fully expanded. The locator arms 70 a, 70 bare free of the implant site. The balloon(s) 180 will be deflated andremoved. The stented valve prosthesis 130 will be securely expanded inthe correct anatomic location.

FIGS. 11A through 11D show the implant of a self-expanding version of anaortic valve prosthesis 190. This is similar to the valve that are soldby Medtronic and St Jude Medical.

As shown in FIG. 11A, the valve 190 is collapsed inside a sheath 62. Avalve locating device 70 has been positioned in the left ventricularoutflow. A guide wire 82 passes through the center of the deliverysystem and extends into the left ventricle 22. The arrow 192 shows thelocating device 70 being pulled back to the correct guiding locationunder the aortic valve leaflets 16, 18. The arms 70 a, 70 b of thissounding or locator device 70 are shorter than previously shown.

As shown in FIG. 11B, the arms 70 a, 70 b of the sounder or locator 70are now in the correct position under the diseased aortic valve 14. Thevalve delivery system 62, 82 is advanced into the correct position asguided by the sounder or guide device 70. This arrangement will ensurethe valve 190 does not sit too low in the annulus 14 a.

FIG. 11B shows a supplemental or optional variation of the sounder orguide device 70 that includes a helix 200. The helix 200 may be helpfulto keep the valve prosthesis 190 centered in the annulus 14. The helix200 could be separate or attached to the sounder device 70 shown in thefigure. The helix 200 is not the only way to center the arms 200. Asecond layer of larger arms (not shown) could be used for example at thelevel of the helix 200.

The aortic valve prosthesis 190 is generally inserted from the groin andaround the aortic arch. The valve 190 typically does not pass directlythrough the center of the annulus 14 a but to one side (the oppositeside from the natural inner turn of the aortic arch). Note that thesesounding devices 70, 200 also serve to center the position of the valvedelivery system 62, 82 in the aortic annulus 14 a. The centered positionmay make delivery more reliable.

As shown in FIG. 11C, the sheath 62 holding the valve 190 is withdrawn(vertical arrow 206 shows the sheath 62 being moved backward) and thevalve 190 begins to spring into position. Arrows 208 show the expansionof the valve 190 laterally. The flared end 190 a of the self-expandingvalve 190 pushes the sounder arms 70 a, 70 b away. The sounder orguide/locator 70 will not be trapped by the stent valve 190. The arms 70a, 70 b will flip over the expanding end 190 a of the valve 190 andavoid being trapped.

FIG. 11D shows the stent valve 190 in the final position. The distance“d” is marked to show the lowest point of the valve 190 sitsconsiderably above the conduction tissue 30.

Referring now to FIG. 12A, during implantation of a prosthetic valve 130using a catheter system 62, 82, there are some high risk periods. Whenthe prosthetic valve 130 is moved inside the native valve 14 the openingfor flow of blood out of the left ventricle 22 is seriously reduced andthe patient can become unstable very quickly. At the same time theimplanter needs to be sure that the valve 130 is positioned safely. Thevalve 130 can sit too high and eject into the aorta 20. The valve 130can sit too low and fall into the ventricle 22. And a valve 130 securelyplaced can still impact against conduction tissue 30. As shown in FIG. 1in the series on valve modifications to avoid heart block, the leftbundle branch LBB (FIGS. 15 and 16) sits just under the aortic valve 14in the area of the junction between the right coronary cusp and thenon-coronary cusp of the native aortic valve 14. Implanting a valve 130even slightly too low can result in heart block. This problem is verycommon with self-expanding valves—where up to 30% of patients maydevelop heart block after the procedure.

As the prosthetic valve 130 is placed inside the native aortic valve 14there is a lot of stress in rushing to complete the procedure to avoidcardiovascular instability coupled with the need to implant at thecorrect level within the valve 14. The implanter has to move veryquickly during this period of time. It makes considerable sense todecide on the location and depth of implant before the prosthetic valve130 is placed inside the native aortic valve 14. This can beaccomplished by using guides or templates that are positionedappropriately before the prosthetic valve 130 is introduced. The guidesor templates have the thickness of guide wires so they have littleeffect on flow. The implanter can take time and position these guidescorrectly and at relative leisure. The valve 130 for implant can bequickly implanted using the positioning template or guide device. Thisleads to high quality implantation and less stress. The time duringwhich the valve 14 is obstructing the outflow (before it is deployed) isvery low.

Clinical experience has shown that implanting a valve 130 so that thelowest part of the valve 130 is no more than 4-5 mm from the bottom ofthe native aortic valve 14, virtually eliminates heart block. Using asounding/positioning/guide, the precise location of the underside of theaortic valve 14 can be identified. This narrow guide device can be setin position at leisure and then the prosthetic valve 130 can be fed overthe guide device or template. The valve 130 can be deployedimmediately—the decision about the location for implantation has alreadybeen made and it has been set by the guide device or template.

The guide device or template can be inserted using a delivery system ofcurrent prosthetic valves.

From a procedural approach, it makes most sense to begin the procedureby introducing a catheter inside the left ventricle and then introducinga guide or template through this catheter into the left ventricle 22.

The guide device or template can then be positioned appropriately underthe native aortic valve 14. This sets the position for the implantprocedure. This decision is made with relatively little obstruction toblood flow from the heart (i.e., only a wire obstructs flow).

For the valve implantation, the prosthetic valve 130 can be fed over thetrack of a wire that serves as a guide device or template and intoposition inside the native aortic valve 14. The valve 130 can beimplanted by inflating a balloon or by unsheathing the valve(self-expanding variety).

The overall effect is to allow a very speedy implant at a pre-determinedsite. There should be less instability for the patient, less stress onthe implanter and a more reliable implantation. Errors due to stress andrushing should be reduced. Inexperienced physicians may be most helpedby this system.

FIG. 12A shows a positioning or locating tool or guiding device 160 thathas a helical shape. It has been placed inside the left ventricle 22through a catheter. The helix 160 has been pulled back until the helix160 contacts the underside of the aortic valve 14. This maneuver willprecisely locate the underside of the valve 14. The implanter will feelthe helix 160 engage against the valve 14 as the helix 160 is drawnback. Also, on fluoroscopy, the helical guide device or helix 160 willbe distorted when the helix 160 is pulled against the native valve 14.

The helical guide device 160 has a proximal wire portion that passes outthe groin of the patient. The wire is passed through a central lumen(not shown) of the prosthetic valve delivery system. The prostheticvalve 130 is then introduced into the patient from the groin. The valve130 shown here is similar to the balloon inflated prosthesis fromEdwards Lifesciences. The template or locator/positioning tool 160 willstop the advance of the prosthetic valve 130 at the appropriate site.The valve 130 will now be in the ideal position. The implanter can nowimmediately begin to expand the valve 130. There is no need to wait andtake multiple images, and multiple steps to ensure the valve 130 is inthe correct position. The implanter can immediately begin to expand thevalve 130.

For a self-expanding valve 190, the implanter can immediately go aheadand unsheathe the delivery system. For a balloon expandable valve 130,the implanter can inflate the balloon 100.

When the valve 130 is in the ideal position inside the native valve 14,the channel for blood flow through the valve 14 is very small. Thisrisky phase is extremely short when the valve position is set by a guideor template 160.

In this figure, the prosthetic valve 130 is stopped or definitivelylocated by a coil of the helix 160. The valve 130 could also be stoppedby a protrusion or deviation (not shown) in the template or locatordevice 160 or any other useful configuration.

Referring to FIG. 12B, immediately after the valve prosthesis 130 ispositioned, the balloon 100 to implant the valve 130 can be inflated.The balloon 100 inflates like a dumb bell. The two ends expand firstbecause the central part of the balloon 100 has the stent frame of thevalve 130 crimped over it. The distal end of the balloon 100 engageswith the helix 160. The helix 160 moves forward or distally into theleft ventricle 22. This keeps the helix 160 from being trapped under theexpanding valve 130.

As shown in FIG. 12C, expansion of the valve 130 continues as theballoon 100 is inflated. The valve prosthesis 130 is now fully expandedinside the native valve 14. The conduction tissue 30 is not contacted bythe stent frame of the valve 130. The valve position is excellent. Thedelivery system and the template 160 can be withdrawn from the patientleaving a prosthetic valve 130 away from the conduction tissue 30. Thesounding or locating or guide device 160 would likely best be made froma shape memory material like Nitinol. This can be shaped in a factoryand then delivered through a catheter. It will be appreciated from areview of the procedure shown in FIGS. 12A through 12C that the helicalguide 160 provides both a level or height-positioning function for thevalve 130 to ensure that the lower portion or margin avoids engagementwith the conduction tissue, but also a centering function for the valve130 to ensure that the valve 130 is not implanted in a manner skewedrelative to the longitudinal (blood flow) axis of the native valve 14.The balloon 100 aids in this centering function, for example, as itsdistal tip engages with the helical guide 160. The guide device 160 maytake other shapes instead.

Referring to FIG. 13A, there are many ways to make a guide, locator ortemplate that performs the function of aiding in the positioning of aprosthetic valve (as these and other synonymous terms are used herein).Interventional specialists commonly use a simple guide wire forconventional purposes in the left ventricle.

FIGS. 13A through 13C show a template or guide device 210 thatintegrates a distal guide wire with a valve positioning guide. It can beinserted as described previously by placing a catheter in the leftventricle 22. The delivery system for the valve 130 can then be fed overthe template 210 to position the valve 130.

As in the previous FIG. 12 series of drawings, the prosthetic valve 130is moved into the inside of the native aortic valve 14 in an ideallocation. As in FIG. 12B, the balloon 100 is inflated as shown in FIG.13B. This moves the helix 210 away from the lower end of the valve 130.

The balloon 100 has been fully inflated as shown in FIG. 13C, and thevalve 130 is in perfect position. The delivery system and the template210 then can be removed from the patient.

FIGS. 14A to 14C show a template or guide device 210 incorporating aguide wire with the template or positioning wire. As describedpreviously, in clinical practice, there is usually a guide wire placedin the left ventricle 22 initially during a procedure.

In these figures the guide wire and the template positioning device arefused or integrated and have a fixed or otherwise unitary but functionalrelationship. It is also possible to slide the template guide over theguide wire. The central guide wire and the template could moveindependently. This would ensure that the guide wire does not cause aninjury to the left ventricle 22—including rupture of the ventricle 22.Also, interventionists are highly experienced in manipulating guidewires to help their valve implant procedure. Allowing separate controlof the template and the guide wire may be helpful.

To link the template guide to the guide wire, a relatively tight spiralof template could wrap around the guide wire. This would hold the twodevices together and they could move independently. In this system thereis no helix to center the system. A centering device is optional withthe template or guide device that positions the level or height of thevalve 190. The implant procedure is the same as described previously.

FIGS. 15 and 16 show the anatomy relevant to the development of heartblock. The aorta 20 is longitudinally opened in illustrative form. Thecusps of the aortic leaflets are shown under the letters L (left), R(right) and N (non-coronary cusp). The orifices of the left and rightcoronaries are shown as apertures 212, 214 in the aorta 20. Below thelevel of the aortic valve 14 is the ventricle 22. The ventricular septum(VS) is shown. This is muscular heart tissue. The mitral valve is markedas MV. The left and right fibrous trigones are marked as LFT and RFT.

The membranous septum (MS) is not composed of muscle, but a thin fibrouslayer that separates the left and right ventricles. On the lower marginof the membranous septum, the conduction tissue is shown here as theleft bundle branch (LBB) or conduction tissue 30. This is the tissuethat carries the signal from the atrium to the ventricles to stimulatethe ventricles to contract as previously described. This tissue islocated just a few millimeters below the native aortic valve 14, so itis easy to see how it can be injured or otherwise disrupted by the frameof an implanted prosthetic valve. The frame of most prosthetic valves iscomposed of a metal stent such as stainless steel or Nitinol. Someprosthetic valves are mounted on a balloon inflatable stent and othersself-expand. In any case it appears any prosthetic valve can injure theconduction tissue and cause heart block.

When a valve frame contacts the conduction tissue 30 the signal for theventricles to contract can be stopped or disrupted. In this case theventricle 22 does not receive the signal from the atrium to contract.The damage to conduction tissue 30 can be immediate. But it is oftendelayed some time. The onset of heart block or conduction damage can bequite unexpected.

Referring to FIG. 17, when an interventionist implants an aorticprosthetic valve, the most critical interest is in ensuring the valve isin a solid and secure position. The natural tendency is to place thevalve quite low—so that a considerable part is located in the leftventricle. This ensures that when the heart beats, the newly implantedvalve is not ejected out of the heart. Unfortunately, if the valve isimplanted low, there is a greater risk of damage to the conductiontissue. FIG. 17 shows the current recommendations for valve placementwhen a balloon inflatable stainless steel valve is placed such as theEdwards Sapien 3 valve. The figure shows the annular plane (i.e., planeof annulus 14 a) as a line along the lowest point of the aortic valvecusps. A marker 220 is located in the center of the unexpanded valve.Earlier, valve implantation was performed at a lower plane. It hasrecently been found that keeping the lowest part of the prosthetic valveless than 4 to 5 mm below the lowest point of the native aortic valve isalmost never associated with heart block development. To accuratelyplace the valve and avoid heart block, the central marker 220 is nowpositioned closer to the annular plane. This has resulted in a muchlower incidence of heart block. But heart block has not been eliminated.And this position may not be ideal for the valve. The prosthetic valvemay function better when positioned or located at a lower level.

FIGS. 18A through 18C are labelled as “prior art.” FIG. 18A shows aballoon expandable aortic valve prosthesis 230 similar to the EdwardsSapien 3 system. A stent portions 232 contains valve leaflets 234 andthis has been crimped on a balloon 240 for delivery. A guide wire 242 isshown passing from the aorta 20 into the left ventricle 22. There is acentral channel in the catheter 244 that mounts the prosthetic valve230. The valve 230 is being guided over the guide wire 242 from theentry site in the groin toward the native aortic valve 14. Theconduction tissue 30 is located below the native valve 14.

In FIG. 18B, the prosthetic valve 230 has been moved inside the nativeaortic valve 14. The balloon 240 will be inflated to expand theprosthetic valve 230 to secure it inside the native valve 14.

In FIG. 18C, the prosthetic valve 230 has been expanded. The stentmounting the valve 230 is now expanded and the valve 230 is securedagainst dislodgement but the valve 230 is expanded against theconduction tissue 30. This patient is at risk for development of aconduction problem or disruption, or heart block.

While these figures show a balloon expandable stent valve 230, there aremany prosthetic valves that are mounted on self-expanding stents,typically made from Nitinol (NiTi). The self-expanding valve can alsoimpinge against the conduction tissue and cause heart conductionproblems.

Referring now to FIGS. 19A through 19C, it would be very useful to avoidthe development of heart block also or alternatively by structuralchanges to a prosthetic valve. Despite a tremendous amount of work todevelop markers and indicators to help physicians properly locate orposition prosthetic valves delivered to an implant site via catheter,heart block unfortunately still occurs commonly—probably in at least 10%of treated patients.

As discussed, it appears that heart block occurs when a portion of thestent engages and compresses against the conduction tissue 30. Theexpanded stent valve or other expandable valve applies a very powerfulforce. It is not surprising this sensitive tissue is injured.

One alternative to avoid the development of heart block is to change thestructure of the stent or the frame of the valve (even if composed ofsomething other than a stent). For example, as discussed, someprosthetic valves are mounted on inflatable structures which can also bephysically design altered to prevent contact with the conduction tissue.

FIGS. 19A, 19B, and 19C show stents associated with valves and havingvariations that will allow the conduction tissue to avoid injury. FIG.19A shows a single “cut-out,” recess or opening 240 along the lowerborder of a stent valve 242 so that the valve 242 can be placed with the“cut-out” opening 240 aligning with the region of the conduction tissue.Specifically, this cut-out, opening or recess 240 is located along thelower edge/margin or circumference of the prosthetic valve 242 and invarious embodiments and may create a discontinuity such that the loweredge is asymmetrical about a plane that bisects the prosthetic valve 242at a location other than at the cut-out, opening or recess 240. Thecut-out, opening or recess 240 must also be located below the area ofthe prosthetic valve leaflets 244 or other valve component that sealswith the adjoining native tissue. As such, the doctor can implant theprosthetic valve 242 at an optimal location within the native aorticvalve 14 and along the longitudinal axes of the native and prostheticvalves 14, 242 and then rotate the prosthetic valve 242 so that thecut-out, opening or recess 240 aligns with the conductive tissue 30. Inthis way, no portion of the prosthetic valve 242 should applyundesirable forces against the conduction tissue 30.

FIG. 19B shows another variation. A single enclosed opening 250 is shownin the stent frame 252. As per the description above, this opening 250is located on the stent frame 252 and the prosthetic valve will beimplanted so that the opening 250 is adjacent to and in alignment withthe conduction tissue 30. In this manner, no portion of the prostheticvalve frame 252 or any other prosthetic valve portion engages anddisrupts or damages the conductive tissue 30.

The opening or recess 250 in the stent structure 252 of the prostheticvalve can be of any shape or configuration that helps to avoid contactand injury to the conduction tissue 30.

It should be noted that the change in the design of the stent frame 252may impact the strength of the frame 252 or its ability to correctlymount the leaflets 244. The stent design can be modified to accommodatefor the loss of the complete circumferential shape of the stent 252 atthe level of the “cut-out,” opening 250 or other configuration of recessmeant to avoid contact with the conductive tissue.

FIG. 19C shows a “cut-out,” recess or opening 260 at the upper margin ofa stent frame 262. Sometimes the upper part of the stent valve 262pushes against native leaflet tissue and impairs flow to the coronaryarteries. A variety of such cut-outs, recesses or openings 260 could beused on the upper margin of the stent 262 to avoid impairment of flow tothe coronary arteries. When the flow to the left main coronary artery isdecreased by a stent pushing the left coronary cusp into the sinus ofValsalva behind the leaflet, the result can be lethal. A cut-out, recessor opening 260 of any shape in the upper part of the leaflet couldprevent this problem. The concepts shown in FIGS. 19A and 19B could alsobe used in the upper part of the stent 262. These figures could beconsidered as candidates to solve this problem in an upside downposition. Specifically, the locations of the upper cut-outs, recesses,or openings 260 are coordinated with the cut-out, opening or recess 250used for avoiding contact with the conduction tissue 30. In this manner,when the cut-outs, openings or recesses 260 along the upper edge arealigned with the coronary openings, the cut-out, opening or recess 250along the lower edge will automatically align with the conductive tissue30. In this manner, contact between the stent valve 252, 262 and boththe coronary arteries and the conductive tissue 30 will be avoided.

FIG. 19D shows a stent valve 270 with an opening or cut-out 272 on itslower margin or edge. It may be useful to cover the opening or cut-out272 in the stent frame 270 with a mesh 274 that is indented to avoidcontact with the conduction tissue 30. The mesh or other material 274may bow or otherwise extend inwardly toward the central longitudinalaxis of the stent valve 270 in order to avoid contact with theconduction tissue 30. The mesh 274 could be made from metal or fromfabric or any other material.

It may be useful to develop a stent valve 270 that is fabricated with apre-formed indentation 272. The indentation 272 would be oriented toextend toward the inside of the stent valve 270 as described above andshown in the drawing so that the stent 270 could be placed with aportion designed to avoid the conduction tissue 30. In this instance, astructurally complete valve frame may be formed in these instances andthe shape chosen to be structurally more sound.

The leaflets 244 are mounted inside the valve stent 270. Their shape andattachment may need modification to adapt them to a modified frame fromthe currently used fashion. Although not shown or described in theembodiments of the FIG. 19 drawing series, any desired covering materialmay be used, such as in the manners described in connection with FIGS.23B and 24B, below or other manners.

FIG. 20 shows a valve 270 shown in FIG. 19D from a side cross sectionalview. A Nitinol stent could be set with a pre-formed indentation 272 sothat there would be a complete stent with an indentation (no structuraldefect but instead a “dimple”) without the need for a separate meshcover.

Stent valves in these figures are generally shown stripped of theirfabric covers, for clarity. Many stents have fabric or plastic covers ontheir surface. These covers could be used in conjunction with thesestent designs. A stent valve could have a cut-out, opening or recess inthe frame and have a fabric covering the cut-out, opening or recessoverlying the conduction tissue. So the valve would be complete andwould not be expected to cause a conduction abnormality.

FIG. 21 shows a self-expanding Nitinol stent valve 280 similar to avalve sold by Medtronic. At the lowest margin or edge of the stent valve280, there is an upside down U-shaped cut-out, opening or recess 282.This cut-out, opening or recess is shown avoiding the conduction tissue.

As described previously, the cut-out, opening or recess 282 in the stentframe could be covered by a layer of plastic or fabric (not shown). Theplastic or fabric would not be expected to damage the conduction tissue30.

The doctor implanting these valves with cut-outs, openings or recessesin the frame will need to rotate the implanted valve to ensure that theexpanded valve is correctly oriented so that the cut-out, opening orrecess 282 is directed toward (i.e., in alignment) the conduction tissue30. Fluoroscopy, echocardiography and other techniques may help thisidentification. Additional markers and guide wires could be placed onthe valve delivery system or stent of the valve 280 to help withorientation.

FIG. 21 shows a prosthetic heart valve stent 280 with a U-shapedcut-out, opening or recess 282 in the inflow portion of the valve 280.The cut-out, opening or recess 282 is designed to avoid contact betweenthe valve frame and the conduction tissue 30.

To facilitate implantation, markers (such as radiopaque markers) couldbe placed on a delivery catheter 284 or on the prosthetic valve 280 tohelp locate the cut-out, opening or recess 282 in the valve frame andorient it correctly with the heart tissue, that is, in alignment withthe conduction tissue 30.

For example, the upside down U-shaped opening at the valve inflow (thatis, on the lower circumferential edge or border) could have markersplaced around the perimeter of the cut-out, opening or recess 282. Ormarkers could be placed just at the ends of the upside down U-shapedcut-out, opening or recess 282 to allow easy identification of themargins of the cut-out, opening or recess 282. These markers 284 couldthen be aligned so that the cut-out, opening or recess 282 at the inflowend of the prosthetic valve 280 could be oriented to overlie theconduction tissue 30. Additional markers could be placed on theprosthetic valve 280 or on the delivery catheter to help with placement.The conduction tissue 30 sits underneath the junction of the right andthe non-coronary aortic valve cusp. The valve prosthesis 280 could berotated and positioned so that the cut-out, opening or recess 282 sitsat the junction of the non-coronary and right coronary cusps of thenative aortic valve 14. During the procedure, the interventionist couldpartially deploy a prosthetic valve 280 such as a self-expanding valveby extruding it from its sheath. The marker or markers could then bevisualized against the native aortic valve 14. The prosthetic valvedelivery system could be rotated and manipulated so that the cut-out,opening or recess 282 in the valve 280 is located in the region of theconduction tissue 30. Ultrasonic guidance may help with identifying thevalve leaflets.

The markers 284 could also be placed on the delivery sheath. Forexample, the valve 280 could be loaded so that the cut-out, opening orrecess 282 was oriented beneath a marker on the delivery sheath ordelivery catheter. The delivery catheter could be rotated so the valveinside the sheath was oriented such that the cut-out, opening or recess282 in the valve 280 is oriented to the conduction tissue 30.

It would also be possible to use markers (not shown) on the prostheticvalve 280 and on the delivery system. This combination may provide thegreatest certainty for appropriate delivery.

To orient the markers on the prosthetic valve 280 or the delivery systemthere are many options. One option would be to identify the rightcoronary artery. The conduction tissue 30 is located under the junctionof the right and non-coronary cusps of the native aortic valve 14. Bylocating the right coronary the valve markers can be rotated withrespect to this location to correctly position the prosthetic valve 280.Also, many patients undergo a CT scan prior to a valve procedure. The CTcan be used to precisely identify the anatomy in the region of thenative valve 14. For example, CT images can be generated that identifythe location of the conduction tissue 30. The plane associated withthese images can then be replicated during the procedure (positioning ofthe patient and the fluoroscopy camera) allowing the interventionistprecise knowledge of the position of the conduction tissue 30.

It should be noted that the shape of the cut-out, opening or recess 282is shown as a U. The shape could vary. It could be V-shaped for example.Also, it could have a more square shape. The depth (or “length” whenmeasured in the direction of blood flow) of the cut-out, opening orrecess 282 could be shallower or deeper (shorter or longer). Theimportant point is to reduce the risk of tissue injury by a prostheticvalve frame. Any design that keeps the prosthetic valve 280 fromengaging against the tissue 30 will be useful.

The prosthetic valve leaflets 244 can be arranged in any way thatproduces a seal inside the valve frame so that blood does notregurgitate inside the heart.

Also, prosthetic valves have covers (not shown) to promote sealing. Theseals could have any relationship to underlying structure of theprosthetic valve 280 and the valve cut-out, opening or recess 282. Theseal could cover the cut-out, opening or recess 282 or the cut-out,opening or recess 282 in the frame could be uncovered or partiallycovered.

Referring now to FIG. 22, Edwards also produces a surgical valve 290that can be implanted without sutures known as Intuity. This valve has amounting stent 292 to hold it in place rather than sutures. This isdepicted in this figure. The mounting stent 292 could have a completecut-out, opening or recess 282 such as the upside down U shape shownpreviously, that could be oriented to avoid contact with conductiontissue (such as in FIG. 21). In FIG. 22 an indentation 294 shown as amesh element 296 attached to a U-shaped border area 298 is shown. Thiscould be a separate and different material or this indented part can beformed as part of the stent 292 that sits underneath the valve leaflets244. In addition, the arched or U-shaped border 298 may be coated orotherwise formed such that it acts as a radiopaque marker for allowingthe doctor to visualize the cut-out, opening or recess 282 onfluoroscopy during the implant procedure.

The cut-out, opening or recess 294 in the frame could be covered by thefabric cover 300 shown over the rest of the valve. The perimeter of thevalve 290 would provide a complete circumferential seal without the highpressure contact against the conduction tissue 30.

The indented part 294 would be oriented by the surgeon to be placed overthe conduction tissue 30. Similarly, there could be a complete cut-out,opening or recess in the stent with no mesh that could be oriented overthe conduction tissue 30 beneath the native leaflets. There could be afabric cover or there could be no fabric cover over this regionincluding the recess or indentation 294.

The surgeon can see the membranous septum during valve surgery so thisvalve 290 can be oriented to ensure the cut-out, opening or recess 294is rotated into alignment with the conduction tissue 30. This area ofthe valve could be marked on the prosthetic valve 290 or its deliverysystem to clearly identify the correct implant orientation of theprosthetic valve 290. The surgeon could rotate and manipulate the valveby visual inspection to ensure the correct orientation of the cut-out,opening or recess 294 in the frame with the conduction tissue 30.

A common goal of these structures is to avoid undue force created by themounting stent 292 against the native conduction tissue 30.

Where a patient has aortic stenosis, the native aortic valve leafletsare stiff and often calcified. Interestingly, there is often a largeamount of calcified material that extends below the diseased valve thatoverlies and continues even below the membranous septum. Sometimes thiscreates a large ball like structure. A cut-out, opening or recess in astent may prevent crushing this material into the conduction tissue. Toensure this material does not break off and embolize, it would be usefulto have a fabric covering over the cut-out, opening or recess in thestent. This cover would contain this material and prevent it frombreaking off.

FIG. 23A shows a self-expanding type of prosthetic aortic valve 310 witha cut-out, opening or recess 312. It should be noted that the inflow ofthe valve 310 sits inside the left ventricle 22 and it flares outward.This outward flare 314 serves to seal the prosthetic valve 310 againstthe heart tissue and to ensure that the prosthetic valve 310 is notforced out of position when the heart ejects blood. Current prostheticvalves have a continuous seal against the left ventricular outflow. Adiscontinuous inflow portion on the prosthetic heart valve 310 may flaremore widely and provide a better seal. The cut-out, opening or recess312 allows the expansion of the inflow of the valve 310 because it doesnot form a complete circle.

The cell construction of the prosthetic stent valve 310 can vary. Anyuseful pattern can be used in conjunction with a cut-out, opening orrecess 312 in the valve inflow.

FIG. 23B shows a prosthetic aortic valve 320 of the self-expandingvariety with three V-shaped cut-outs, openings or recesses 322. Asdescribed previously, the cut-outs, openings or recesses 322 can takeany shape. The edges of the inflow portion of the prosthetic valve, asshown in this figure, may be sharp. In clinical use it may be useful tohave more rounded edges to prevent injury to the heart and to easydelivery. The valve 320 shown here has a fabric cover 324. The cover 324can be arranged in any useful way over the valve frame. The cover 324could also be incomplete. In other words, the cover 324 may not be onthe entire underlying stent frame. Although covers are not shown on manyof the embodiments shown and described herein, it will be appreciatedthat such covering material will be used on prosthetic heart valves suchas these, as necessary or desired. The covering material may be in anyconventional or desired construction, such as knit or woven fabrics thatpromote tissue in growth. Respective cut-outs in the covering 324preferably coincide or align with the cut-outs 322. In this manner, whenone of the cut-outs 322 is aligned with the conduction tissue 20, thereis less chance of interference by any valve material with the signalstravelling through the conduction tissue 30. Although three cut-outs 322shown, a different number may be designed into the valve 320, and inthis regard forming the valve 320 with only a single cut-out 322 hasdistinct advantages in that more of the valve surface area or coveringmaterial 324 is available for sealing blood flow after implantation. Asan alternative, the covering material 324 may cover the cut-out 322 inthe stent frame, on the outside of the frame, assuming it is found thatthis would not interfere with the conduction tissue. As mentioned, theseconcepts may be applied to any of the embodiments shown and describedherein. The three cut-outs, openings or recesses 322 in the valve 320are all shown with a similar shape. The cut-outs, openings or recesses322 could be different. Some could be V-shaped and others U-shaped. Alsothe cut-outs, openings or recesses 322 could be at different depths. Forexample, there could be a more shallow outflaring of the prostheticvalve 320 near the conduction tissue 30. These edges of the inflow ofthe prosthetic valve 320 can be thought of as tabs 328. There could bemore than three. There could be areas where there are no tabs 328—forexample near the conduction tissue 30. There could be no prostheticvalve structure in the region of the conduction tissue 30 and tabs (along single tab or multiple tabs) located around the rest of theperimeter of the inflow portion.

FIGS. 24A and 24B show an embodiment of a prosthetic aortic valve 340with a discontinuous inflow portion or edge when viewed in the inflowplane.

There are three separate cut-outs, openings or recesses 342. This willallow the valve 340 to be easily rotated to avoid the conduction tissue30. With only one cut-out, opening or recess 342 the amount of rotationnecessary to align the cut-out, opening or recess 342 with theconduction tissue 30 could be considerable. However, this may bemitigated by implantation techniques that pre-orient the valve, forexample, as described herein. The description of the embodiment inconnection with FIG. 23B generally applies here with the differencebeing the shape or configuration of the valve 340.

Also, since the conduction tissue 30 is located beneath the junction ofthe right and non-coronary cusps of the native valve, this symmetricarrangement may be easier to align with the native aortic valve 14 toensure good placement. The prosthetic valve 340 can be “matched” withthe native valve 14.

“Tabs” or fingers/arms 346 are formed but could be much narrower thanshown. These tabs 346 will provide good contact and flare against theoutflow of the left ventricle 22 to keep the prosthetic valve 340securely in place. The narrow “tabs” 346 will have a lower likelihood ofcontacting the conduction tissue 30. The tabs 346 could also beconfigured to “flare”—that is to extent out radially from the centralaxis of the valve 340 and contact the heart tissue in the outflow regionof the left ventricle 22.

Many implanters prefer to use a self-expanding valve. This valve has theadvantage that it can be extruded (at least partly) from its deliverysheath or delivery system, and if the position is not ideal, the valvecan be re-sheathed and repositioned until it is in the correct position.Unfortunately, the risk of heart block is higher with a self-expandingvalve. So an ideal situation for clinical practice would be a valve thatis re-sheathable and repositionable while also carrying a low risk ofheart block. A valve with tabs 346 could solve this problem.

FIGS. 25A and 25B show a prosthetic valve 350 more typically made fromstainless steel and expanded with a balloon. This valve 350 can alsohave the addition of multiple cut-outs or recesses 352. The valve 350shown here has three cut-outs or recesses 352.

As described previously, there can be many arrangements with differentshaped cut-outs, openings or recesses (U-shaped, V-shaped etc.) anddifferent depths of tabs. The depths or lengths of the tabs on the sameprosthetic valve could also vary. For example, tabs placed near theconduction tissue could be shallow (short). Other tabs could be longerfor greater retention.

Referring to FIG. 26A, when a physician implants a prosthetic aorticvalve, the first concern is that placement is too low—where the valvefalls into the left ventricle 22 or too high—where the valve releasesfrom the aortic position and can travel farther into the aorta 20. Therisk of dislodgement into the aorta 20 is the biggest fear, sonaturally, the strong tendency is to place the valve in a lowerposition. The lower position is, however, more likely to contact theconduction tissue 30.

FIG. 26A shows another prosthetic valve 360. The locations of theleaflets 244 are shown in the dotted lines. The valve 360 has anextension below the leaflets 244 that includes tabs 362 that sit insidethe left ventricular outflow. These tabs flare out radially to conformto the left ventricular outflow tract. They can be flared by theexpansion of a balloon that inflates the valve 360. Since the inflow ofthe valve 360 is discontinuous when viewed in the plane of the inflow,the balloon inflation will naturally result in flaring of the tabs 362.This will engage the valve 360 against the inside of the heart and keepit solidly in place. A self-expanding valve can also be formed in thisway. The tabs 362 could be constructed to flare out after the valve 360is delivered. By orienting the tabs 362 away from the conduction tissue30, the risk of the conduction tissue 30 being injured is low.

FIGS. 26A-26C show three tabs 362. There could be more or fewer. Thetabs 362 could be wider or narrower. The tabs 362 are shown symmetric.They could be asymmetric. There could also be gaps between the tabs362—especially to accommodate placement in the region of the conductiontissue. When this valve 360 is expanded, the implanter will feel astrong sense of security that the prosthetic valve 360 is in goodposition, stable and with low risk of ejection from the heart as well asconfidence that the conduction tissue 30 will be free from injury. Allof these tab concepts can be applied to any type of valve includingself-expanding (Nitinol type) and balloon expanding (stainless steel).And, as with all embodiments and features disclosed herein, the variousfeatures may be used alone or in any combination depending on thedesired results and functions. Another variation on a tab is to have atab that is almost circumferential with only a gap in one area of thevalve. The large tab would extend almost circumferentially around thevalve.

FIG. 26A shows the valve leaflets 244 (dotted) and tabs 362 whichfunction as extensions below the inflow of the valve 360. The leaflets244 of the prosthetic valve 360 sit above the tabs 362. The leaflets 244sit inside the tubular part of the valve 360. This means that therelationship between the leaflets 244 and the stent support is constantand largely independent of the added tabs 362. This may be a very usefularrangement. The current prosthetic valve design for both aself-expanding and a balloon inflated valve would not be seriouslyimpacted by the addition of tabs 362. The mechanical stability and theway the leaflets 244 are supported by the stent would not be materiallychanged. It is likely that durability testing would not change and sothere would be less expense in re-designing a new valve with these tabextensions. This is a long and costly endeavor requiring extensiveengineering modeling and bench testing for stress and strain on thevalve and finally animal durability testing and human testing. Addingtabs 362 should not require considerable additional testing. Also, oneof the main costs for introducing a new valve concern the regulatoryrequirements from governments to allow use in patients. The fact thevalve 360 in these figures functions like previous valves should reducethe cost of satisfying regulators before initiating sales of a device.Manufacturers can rely largely on their extensive experience withcurrent valves to satisfy regulators.

FIG. 26A shows leaflets 244 that are sitting above the tabs 362. Itwould also be possible to position the leaflets 244 such that the cuspsof the leaflets 244 follow the curved lower surface of the inflow on theprosthetic valve 360—the scalloped shape. The leaflets 244 could bepositioned lower than shown in the figures. This would allow theimplantation of larger cusps and also allow placement of a valve with aclosure point even below the closing point of a natural aortic valve.The prosthetic valve leaflets 244 could sit lower inside the stentframe—along the flared part of the prosthetic valve 360. The valvediameter is larger in the flared part of the valve 360. The prostheticvalve area would be larger, reducing the gradient to flow out of theheart. In patients with very small outflow regions in the heart,positioning of a valve 360 may cause serious obstruction to bloodoutflow and this causes increased load on the heart. Placing the valvelower—even inside the left ventricle 22 where there is more space, mayreduce the amount of obstruction to the outflow of blood from theventricle. Currently, there is no possibility of subannular placement ofprosthetic heart valves in the aortic position. In some patients thereis a risk of obstruction of the coronary arteries with prosthetic valveplacement. Lower placement of the prosthetic valve may be important inthese patients.

FIGS. 26B and 26C show valve 360 with tab extensions 362. The valve 360has been opened for easy viewing. This is shown only as an example. Thestent cell pattern can be in any useful pattern. The key is that thereis a single or multiple cut-outs, openings or recesses 364 to avoidcontact with the conduction tissue 30. A self-expanding stent valvecould also benefit from these features. Radiopaque markers 366 line thegaps 364 so that the doctor can more easily visualize correctpositioning under fluoroscopy, especially aligning one of the gaps 364with the conduction tissue. It will be appreciated that any of theprosthetic valves described herein as including a cut-out, opening orrecess (i.e., a gap) may likewise include at least one radiopaque markeradjacent the cut-out, opening or recess for visualization andpositioning purposes during the implantation procedure.

FIG. 27 shows the prosthetic valve 360 with tabs 362 in position insidethe heart. The valve 360 is very secure. The tabs 362 flare out andprovide excellent protection against the valve exiting the heart. Whenthe tabs 362 are oriented out of contact with the conduction tissue 30,there is reduced risk of heart block. The tabs 362 could be more or lessturned. The tabs 362 could be longer or shorter. The tabs 362 could varyin length. While difficult to visualize, it should be noted that the tab362 on the left in this figure is behind the conductive tissue 30 andtherefore a gap (i.e., a cut-out, opening or recess) between adjacenttabs 362 aligns with the conductive tissue 30.

FIG. 28A-1 is an image of the aortic root after it has been filled withcontrast dye. The contrast has been injected through a pig tail catheter370 that sits in the non-coronary cusp of the aortic valve 14. The threecusps of the aortic valve 14 are clearly evident. There is anechocardiography probe sitting in the esophagus adjacent to the heart.The large left coronary artery is shown filled with dye passing over theleft ventricle.

FIG. 28A-2 is a drawing that illustrates the features evident in theangiographic image of FIG. 28A-1. The pig tail catheter 370 is shown forthe injection of dye. It sits in the non-coronary cusp N. There arethree coronary cusps all marked by letters. They are the N ornon-coronary cusp, R or right coronary cusp and L or left coronary cusp.The left coronary 372 is also shown exiting from the left coronary cuspL.

Most important is the location of the conduction tissue 30. This tissue30 sits below the junction of the non-coronary (N) and right coronary(R) cusps. This is a very reliable anatomic location. By avoidingcontact between a valve prosthesis and the conduction tissue 30, heartblock can be avoided.

FIG. 28B shows the aortic root filled with dye. The labels are identicalto FIG. 28A-2.

FIG. 28C shows an aortic valve prosthesis 380 of the balloon expandingvariety. The valve 380 has been collapsed inside a sheath 62 fordelivery into the patient, usually from the groin region. The prostheticvalve 380 is shown advanced inside the diseased native aortic valve 14.The prosthetic valve 380 inside the sheath 62 has two flanges or tabs382. The flanges or tabs 382 on the valve 380 are marked with radiopaquemarkers 388. This allows the interventionist to rotate the prostheticvalve 380 so that the gap or recess or cut-out 384 between the flangesor tabs 382 will sit between the non-coronary cusp N and the rightcoronary cusp R. This will ensure that the gap 384 between the flangesor tabs 382 will lie in the region of the conduction tissue 30. It willnot contact conduction tissue 30.

The location of the native valve cusps can be determined using anangiogram as shown in FIG. 28A-1. Once a prosthetic valve 380 isadvanced inside the diseased native aortic valve annulus, the outflow ofblood from the heart can be obstructed and the patient can quicklybecome hemodynamically unstable. The valve 380 could be rotated into theappropriate position inside the native valve 14, but it is likely saferto perform this rotation before the valve 380 is advanced into positioninside the native valve 14. The operator can take the time necessary toproperly rotate the valve 380 relative to the position of the patient'snative valve leaflets while the prosthetic valve 380 sits in thedelivery system and is still located above the native aortic valve 14inside the ascending aorta 20.

In FIG. 28D, the prosthetic valve 380 has now been released andimplanted. The gap 384 between the flanges 382 is oriented at the regionof the junction between the right and non-coronary cusps R, N. Thismeans the gap 384 will be oriented so that prosthetic valve 380 does notengage the conduction tissue 30.

The valve 380 shown in this series of figures has two gaps 384 and twoflanges 382. Previous figures have shown other numbers of gaps andflanges. A single flange construction with only one gap 384 in theprosthetic valve 380 may be preferred by interventional cardiologistsbecause it increases the amount of seal to avoid a leak around theprosthesis. Or three flanges or tabs 382 may be preferred as the valve380 could be oriented with the patient's native valve 14. The number offlanges 382 and gaps 384 is not critical, just the avoidance of contactbetween the prosthetic valve 380 and the conduction tissue 30.

Radiopaque markers 388 are shown on the prosthetic valve 380 in FIG.28D. The markers 388 to show the location of the flanges 382 could alsobe located on the delivery system or delivery sheath. There could alsobe markers on both the delivery system and the valve. The markers couldbe different on different flanges. For example, there could be two markson one side of a gap 384 and one mark on the other side of the gap 384in the valve. Or different shapes of radiopaque marker could be used ondifferent sides of the gap 384 between flanges 382.

FIG. 29A shows the general shape of the prosthetic valve 380 that hastwo flanges 382 in the inflow region. The inflow region does not sit inone plane. This general construction can be adapted for use with balloonexpandable (Edwards), self-expanding (Medtronic and St Jude) and Nitinolwire type valves (Lotus type). A valve of any current or futureconstruction could use such features. As explained previously, therecould be different numbers of gaps 384 and flanges 382 than two. Onemight be preferred as this would provide a lower and longer seal toprevent paravalve leaks.

FIG. 29B shows a stent structure 390 for the prosthetic valve frame thatmay be used for valve 380. In dotted lines inside the frame 390, thevalve leaflets 244 are shown. These are typically made from animal orbiologic materials but they can be biocompatible artificial materials orbioengineered materials also.

FIG. 29C shows a top view of a prosthetic valve 380. The leaflets 244are shown.

FIG. 30A shows a view from above of the native aortic valve root. Theleft (L), right (R), and non (N) coronary cusps of the valve 14 arelabelled. The right coronary and left coronary arteries 392, 394 areshown coming off their corresponding sinuses of the aortic valve 14. Theconduction tissue 30 sits under the junction of the right andnon-coronary cusps R, N.

FIG. 30B shows the prosthetic valve 380 positioned inside the nativeaortic root. The prosthetic valve flanges 382 have radiopaque markers388. These are used to orient the valve 380 in position so that the gap384 in the valve 380 sits at the junction of the right and non-coronarycusps R, N. It is clear that the valve frame does not engage theconduction tissue 30. For orientation, the location of the originalposition of the native leaflets is shown (before valve implantation)with dotted lines.

FIGS. 31A-1 and 31A-2 are identical to FIGS. 28A-1 and 28A-2. The threecusps R, N, L of the native valve 14 and the location of the conductiontissue 30 are shown. A rotation and repositioning of the imaging cameraangle is indicated by the arrow 398. Rotating the camera angle canproduce an image that highlights the junction between the non-coronaryand right coronary cusps N, R. The camera used in the catheterizationlab is rotated right and left over the patient. There is also anadjustment in the camera for the cranial and caudal pitch of the camera.

FIG. 31B-1 shows an angiogram of the aortic root. FIG. 31B-2 is adrawing that corresponds to this angiogram and where the features arelabelled. The figures show the non-coronary cusp (N) on the left. Theright coronary cusp (R) is on the right. The conduction tissue 30 isshown as a circular region below the plane of the valve 14. This aorticroot angiogram can be readily produced on angiography by having thecorrect camera position over the patient. This position clearlydemonstrates a good image for implanting a valve with a gap. Thisangiography view clearly shows the correct orientation for a prostheticvalve that is to be implanted to avoid contact with the conductiontissue. There are a number of options to produce this view. One optionwould be to perform a baseline aortic root injection while moving acamera to identify an ideal angle to produce a view similar to thisangiogram. This baseline angiogram would then be used to identify camerapositions suitable to perform the prosthetic valve implant procedure.

Many interventional cardiologists prefer not to inject any additionaldye. Angiographic dye can be toxic to the kidneys. Prior to valveimplantation, a baseline image with a CT scan is often taken. Theseimages can be used to plan the procedure. Current software is highlyeffective in reconstructing images of the aortic root. One commonly usedsystem is 3Mensio. This CT finding tool (as well as others) can be usedto predict with a high level of accuracy the exact camera angle thatwill be necessary to show the non-coronary cusp on the left and theright coronary cusp on the right. This is the camera angle that was usedto produce the angiographic image in FIG. 31B-1. For example, the CTanalysis tool may find that a typical camera angle to image the aorticvalve and demonstrate the junction between the right and non-coronarycusps is about ten degrees RAO (Right Anterior Oblique) and with about10 degrees of caudal tilt. Patients vary in the position and orientationof their aortic root and in their body habitus. So this tool could beused to prevent the need for a full dye injection. Once the CT has beenused to predict the ideal camera angle, the interventionist could placea pig tail catheter 370 in the non-coronary cusp N, position theangiographic camera at the predicted location and inject a small puff ofdye to ensure the predicted angle was correct. Slight adjustments may benecessary to obtain the ideal camera angle. Ultimately, if theprediction from CT imaging is proved to be sufficiently accurate, thisstep of flushing the aortic root could be avoided. It should be notedthat the valve designs shown have a considerable gap between theflanges. There may be a small error in the predicted camera angle, butsince the flanges miss a considerable amount of the native valveannulus, it may not be necessary to perfectly orientate the prostheticvalve inside the native aortic valve.

Other imaging techniques such as transthoracic ultrasound,trans-esophageal ultrasound and MR scanning could also be used toprovide the information to position the camera for valve implantation.Sometimes valve leaflets are heavily calcified. The calcification of theleaflets may define the shape and location of the leaflets without dyeinjection. So in some patients, imaging with fluoroscopy of the leafletsalone (or in combination with information from other imaging modalities)may provide the correct position for imaging the non-coronary to rightcoronary cusp junction.

The same procedure of defining the location of the commissure betweenthe right and non-coronary cusps R, N could be used to implant aprosthetic valve with one gap. The gap would be implanted straddlingthis commissure junction.

The positioning of the prosthetic valve is ideally done before the valveis placed inside the native aortic root. The prosthetic valve can bepositioned and rotated above the native aortic valve. The position ofthe native leaflets and the position of the prosthetic valve can beimaged. The prosthetic valve can then be rotated and using the guidanceof markers on the delivery system or the valve itself, the correctorientation of the prosthesis can be determined. After this can becompleted, the valve can be advanced through the native aortic annulusand rapidly deployed. As indicated previously, the patient may becomehemodynamically unstable once the prosthetic valve is moved inside thenative leaflets, so it seems prudent to orient a prosthetic valve beforeplacing it inside the native aortic valve annulus.

Radiopaque markers can vary in their location. The key is that theyprovide information on how to orient the valve to avoid the prostheticvalve contacting the conduction tissue.

FIG. 31C shows a prosthetic valve 400 with two flanges or tabs 402. Eachflange 402 is marked with a radiopaque marker 404. The valve 400 hasbeen rotated so that the markers 404 have been positioned so that onemarker 404 is located toward the non-coronary cusp N and the othertoward the right coronary cusp R. This can be done by rotating theprosthetic valve 400 so that the radiopaque markers 404 are maximallyspread apart from each other when viewed in an angiographic image suchas shown in FIG. 31A-1. As stated previously, there are many ways to usethe angiographic markers 404. There could be different shaped or numbersof markers 404. A marker 404 could be placed on the highest point of theinflow of the prosthetic valve 400 and this marker 404 could be orientedto the location of the right and non-coronary cusps R, N.

Once the prosthetic valve 400 has been introduced inside the nativeleaflets, it can be unsheathed and released in the correct orientation.The gap 406 between the flanges 402 is shown oriented with theconduction tissue 30.

FIG. 31D shows the final position of the implanted valve 400. The valve400 has two flanges 402 oriented safely away from the conduction tissue30. As mentioned previously, the number of gaps 406 and flanges 402could be varied. The shapes and number of the radiographic markers 404could be adjusted. Additional markers 404 may be useful. For example, itmay be useful to add a marker 404 half way between the two flanges 402.Such a marker 404 would identify the highest point of the inflow end ofthe prosthetic valve 400.

The flanges 402 shown on this valve 400 are equal in size. The flanges402 could be unequal. Some patients have a very “horizontal” aorticarch. In these patients, the aorta does not demonstrate the typical Uturn shown in textbooks. When a prosthetic valve is introduced from thegroin through a horizontal arch, it often is released on a slightlyeccentric angle. By making one flange longer, wider or larger than theother, it may be possible release the prosthetic valve 400 so that isbetter aligned with the native aortic root and the left ventricularoutflow. In a typical procedure, the interventionist releases aself-expanding valve partially inside the left ventricle and then drawsthe catheter out of the heart until it engages with the native aorticvalve and left ventricular outflow. A longer flange on one side of theprosthesis 400 may engage with the heart on one side of the leftventricular outflow and straighten the prosthetic valve 400 so that isaligned more precisely with the left ventricular outflow.

Helical devices have been described herein to assist in correctplacement of the prosthetic aortic valve. These helical devices can helpto position the depth of placement of a valve so that the valve does notimpact against conduction tissue 30 sitting below the annulus 14 a.These devices can also ensure that the valve implantation starts from acentral position inside the annulus 14 a so that the expanded valve isimplanted parallel to the left ventricular outflow. When the aorta 20 is“horizontal” the native valve 14 can be approached at a skewed angle bythe catheter that implants the valve prosthesis. The use of a helixensures that the valve implantation is begun at the center of the nativeannulus.

FIG. 32A shows an additional feature on a helical guide device 420. Thisfeature is the addition of one or more radiopaque markers 422. Themarker 422 in this figure can be rotated and positioned to identify thelocation of the conduction tissue 30. In this figure, the marker 422 hasbeen positioned just below the junction of the right and non-coronarycusps R, N—where the conduction tissue 30 sits. The marker 422 on thehelix 420 can then be aligned relative to the markers 424 on theprosthetic valve flanges 426. This ensures the gap 428 between theflanges 426 will sit over the conduction tissue 30.

Additional radiopaque markers could be placed on the straight segment ofthe positioning or guide device 420 to indicate the depth of valveimplant 430. For example, the helix 420 could be pulled back against theunderside of the leaflets of the native aortic valve 14. Anotherradiopaque marker (not shown) could indicate how far down thepositioning or guide device 420 the interventionist should locate theprosthetic valve 430 for implantation.

To perform this procedure, the interventionist would place the helix 420inside the left ventricle 22 and align the marker 422 with the positionof the conduction tissue 30. The valve 430 and its delivery catheter 62could then be advanced over the helical device 420 and positioned insidethe annulus 14 a with care to orient the markers 424 on the prostheticvalve 430 appropriately with the helix marker 422. The sheath 62covering the valve 430 can be removed and the valve positioned. In thisarrangement, the helical guide 420 has three functions—1) it helpsdetermine the depth of implant, 2) it orients the valve prosthesis 430correctly relative to the commissures or cusps N, R, L and conductiontissue 30 and 3) it assures that valve release will begin in the centerof the annulus 14 a and that the valve 430 will be expanded in adirection parallel to the left ventricular outflow and the aorta 20. Itcan make the entire procedure safer—reducing the time needed to adjustthe prosthesis 430 while it is sitting unreleased inside the annulus 14a before it is released.

Previously, a variety of devices have been shown that assist inpositioning a prosthetic aortic valve 430. FIG. 32B shows anothervariation of a valve positioning or guide device 440. This figure showsan expandable basket device 440. The basket 440 can be inserted insidethe left ventricle 22 at the end of a delivery wire 442. The basket 440is delivered in a closed shape. The valve 430 and its delivery systemcan be advanced over this device 440.

FIG. 32C shows the basket 440 expanded inside the left ventricularoutflow. There are radiopaque markers 444 shown on the basket 440. Themarkers 444 are located on arms 446. The conduction tissue 30 in thisarrangement is located in the center of the markers 444. The prostheticvalve 430 with the flanges 426 is rotated so that each flange 426 isdirected toward one marker 444 on the basket 440. Many differentpatterns of radiopaque markers 444 could be used. The key item is thatthe markers 444 on the positioning device 440 can be oriented relativeto the conduction tissue 30. Then the valve 430 for implantation can beoriented relative to the positioning device 440. Any marker arrangementthat helps to avoid valve implantation in contact with conduction tissue30 is useful.

The depth of the basket device 440 can be adjusted to help control thedepth of the implant. Additional radiopaque markers could be placed onthe straight segment 448 of the positioning device 440 to indicate tothe cardiologist where to place the distal tip of the valve deliverysystem. Previously, the turn in the wire leading into the helix has beenshown as a “stopper” for valve positioning depth. In this variation, thetop 450 of the basket device 440 could be used as a “stopper” toindicate where the valve implantation should start.

The basket 440 could vary in shape. For example, there could be anindentation (not shown) at the upper end of the basket 440 toaccommodate the valve.

This device 440 again serves three functions—1) It helps determine thedepth of the implant of the prosthetic valve 430 inside the annulus 14a, 2) It helps center the implantation of the valve 430 inside theannulus 14 a (particularly helpful in the short horizontal aorta) and 3)It helps orient the implant of the prosthetic valve 430 to avoid injuryto conduction tissue 30. Further, it can make the procedure faster andsafer—even for less skilled interventionists.

FIGS. 33A1, 33A2, 33B, 33C and 33D show a sequence for implantation of aLotus type valve 450 (sold by Boston Scientific). This valve 450 iscomposed of a mesh of wires. The valve 450 is delivered in a lengthenedshape and then the mesh shortens as the valve 450 is implanted insidethe native valve 14. The valve variation in these figures show that aLotus type valve 450 can be structurally changed to have an inflow gap452 that avoids the conduction tissue 30. This valve 450 is shown withtwo gaps 452. As with all the other valves, there could be one or moregaps 452 in the construction. Radiopaque markers 456 can be added tolocate the position of the flanges or tabs 458 on the valve. These areshown in FIG. 33B. The location of the highest point on the inflow couldalso be identified with a radiopaque marker 460. It should be noted thatthe valve variations shown in all of these figure series havedemonstrated two inflow flanges 458. The same concepts could apply tomore or few flanges 458 or to the use of valves made with U-shaped,cut-outs or recesses or circular cut-outs or recesses that have beenshown previously.

Referring to FIG. 34, the plane of the aortic valve in a typical patientis not horizontal. The valve plane is lower on the patient's right andhigher on the patient's left side. To image in the plane of the aorticvalve cardiologists have developed estimates for commonly used cameraangles for visualization of the aortic valve in plane. This figure showsthe range of typical camera angles in a left and right plane and in anup and down plane that are helpful in planning imaging of the aorticvalve. One axis of the figure shows the left and right camera anglepositions—RAO (right anterior oblique) and LAO (left anterior oblique).The other axis shows the up and down camera positions. The upper angles(toward the patient's head) are identified as Cranial. The lower angles(toward the patient's feet) are marked as Caudal. The figure shows thatthe plane of the aortic valve generally travels from lower on the rightto upper on the left. The error bars indicate that there is a wide rangeof variation between individual patients.

FIG. 34 is useful because it can provide a starting estimate for imagingin the plane of the aortic valve 14. The typical location of thejunction between the right and non-coronary aortic cusps R, N sits alongthis general plane and is most commonly a little right of the midline.So a typical junction between the right and non-coronary cusps R, N maybe best imaged with a camera positioned in the region shown in thedashed area 460.

This starting information is useful. A cardiologist can start aprocedure with these coordinates in mind and then refine thelocalization of the commissural junction by injecting a small amount ofcontrast dye.

CT of the aortic root with contrast is almost always done prior a valveimplant procedure to assess the dimensions of the aortic annulus toassist in selection of an appropriately sized trans-catheter heart valve(THV) implant. These images can also be used to predict the optimalfluoroscopy projections to be used during implantation. These same CTimages can easily be used to predict optimal imaging projections for theNC (non-coronary) to R (right) cusp commissure. Ultrasound and MR mayalso help to precisely guide best imaging coordinates.

FIG. 35 shows the introduction of a percutaneous aortic valve prosthesisfrom the right groin region of a patient. Typically, an introducersheath 62 is placed in the artery in a groin. The collapsed prostheticvalve 470 and its delivery system are advanced from the groin artery, upthe aorta 20 and to its position inside the native aortic valve 14. Thepatient's aorta 20 follows close to the vertebral column, usually juston the left side of the aorta 20. So, the aorta 20 is close to the backof the patient. The aorta 20 has an arch which turns forward and to theleft side of the patient. So, the prosthetic valve 470 will be directedup the aorta 20 traveling close to the patient's back, and then makes aroughly U-shaped turn forward toward the front of the patient as itsimultaneously curves to the left. As an approximation, the part of theprosthetic valve 470 that is introduced at the groin will bend forwardso that the part of the prosthesis 470 that is directed toward the backof the patient at entry in the groin will end up towards the front ofthe patient when the valve prosthesis 470 passes around the aortic arch.The ideal orientation for the part of the valve prosthesis 470 thatavoids the conduction tissue 30 is approximately fifteen degrees to theright. Therefore, it is possible to avoid rotations inside the aorta 20for the prosthesis 470 by introducing the part of the valve 470 that isintended to be placed at the junction of the right and non-coronarycusps R, N toward the back of the patient, with a rotation that bringsthe part of the prosthesis 470 that avoids the conduction tissue 30rotated to account for this final, desired location or orientation.

The correct orientation, and location from a rotational standpoint forthe valve prosthesis 470 can generally be estimated by theinterventionist. Or, the images from CT, MR or information fromecho-ultrasound or any modality can be used to precisely predict theideal insertion orientation. The exact course of the femoral, iliac,aorta, aortic arch and the orientation of the native valve 14 can beused to predict the correct orientation. An algorism may be producedfrom imaging modalities to help the interventionist to improve theaccuracy of the insertion orientation of the valve prosthesis 470. Themore accurate the insertion, the less the need to rotate the valveprosthesis 470 once it is placed at the implantation site.

FIG. 35A shows an enlarged view of the valve prosthesis 470 beingoriented in an angular or rotational sense during its insertion insidethe femoral artery 472. It would be very useful to introduce the valveprosthesis 470 into the femoral artery at an orientation that results inthe part of the prosthetic valve 470 that is designed to avoid theconduction tissue 30 arriving at the native aortic valve 14 at thejunction of the right and non-coronary cusps R, L. As previouslydiscussed, this would place the cut-out, recess, or gap etc. that isdesigned to avoid the conduction tissue 30 in alignment with thatconduction tissue 30. This portion of the inventive procedure can begenerally predicted from understanding the course or path of the aorta20. Further refinements may be made using data from scans showing eachpatient's individual anatomy. Ideally, the valve prosthesis insertionshould be perfect, i.e., there would not be a need in this case toadjust the rotation of the prosthetic valve 470 inside the patient'saorta or at the implantation site. Most likely, any estimate and even analgorithm will be slightly off from the idea position. But, the need fora rotation or adjustment at the implantation site may be reduced to justa few degrees of rotation, thereby reducing the time and the riskassociated with the procedure.

FIGS. 36A and 36B respectively show a collapsed and an expanded versionof an inflatable aortic prosthetic valve 480 that avoids contact withthe conduction tissue 30 in a manner similar to those previouslydescribed. Many previous variations have been shown for the constructionof prosthetic valves that avoid contact with the conduction tissue 30.While this not the only form that an inflatable prosthetic valve maytake, it nevertheless illustrates the key point of avoiding contact withthe conduction tissue 30 through the formation of a gap, cut-out orrecess 482 in the valve 480, and orienting that gap, cut-out, recess, orother structural void in the prosthetic valve over or in alignment withthe conduction tissue 30. In this embodiment the valve 480 includescut-outs, openings or recesses 482 at the lower margin separated by armsor tabs 484 flaring or extending radially outward from the lower marginor ring 34. These tabs 484 include radiopaque markers 486 to assist theinterventionist in placing and orienting the valve 480. Specifically,the interventionist will be assured that no portion of the valve 480negatively contacts or engages the conduction tissue 30.

Various disclosure and descriptions herein have focused on implantationof a prosthetic valve with two flanges. The same procedures and methodscould be used to implant a valve with one or three flanges.

A three flanged valve might best be implanted by orienting theprosthetic valve with the native aortic valve. It could follow thescallops of the native valve and the anchor for the valve would notcontact conduction tissue.

Although not shown here, these same concepts could be extended to mitralor other valve implantation. Templates or guides could be constructed toimprove the implant of a prosthetic mitral valve.

1. A prosthetic aortic valve for mounting at an implant site associatedwith a native aortic valve of a patient, comprising: a stent frameformed from wire, the stent frame including an upper margin or edge, alower margin or edge, and an interior, wherein the stent frame includesonly a single cut-out, opening or recess located along the lower marginor edge configured to align with conduction tissue below the nativeaortic valve to prevent contact by any structural element of the stentframe with the conduction tissue while providing more valve surface areaat the lower margin for sealing blood flow after implantation, and aplurality of prosthetic valve leaflets mounted within the interior ofthe stent frame to provide unidirectional flow of blood through theprosthetic aortic valve.
 2. The valve of claim 1 wherein the cut-out,opening or recess is generally U-shaped or V-shaped or generally squareshaped.
 3. The valve of claim 1 wherein the cut-out, opening or recessis generally curved in shape.
 4. The valve of claim 1, wherein thecut-out, opening or recess further comprises an indentation in the stentframe so the frame avoids compressing the conduction tissue.
 5. Thevalve of claim 1, further comprising a covering material attached overthe cut-out, opening or recess.
 6. The valve of claim 1, furthercomprising at least one radiopaque marker placed adjacent opposite edgesof the cut-out, opening or recess to aid in the correct orientation ofthe valve during implantation in relationship to the conduction tissue.7. A prosthetic aortic valve for mounting at an implant site associatedwith a native aortic valve of a patient, comprising: a stent frameformed from wire, the stent frame including an upper margin or edge, alower margin or edge, and an interior, wherein the stent frame includesa plurality of spaced apart cut-outs, openings or recesses located alongthe lower margin or edge, wherein one of the cut-outs, openings orrecesses may be aligned with conduction tissue below the native aorticvalve to prevent contact by any structural element of the stent framewith the conduction tissue, a plurality of prosthetic valve leafletsmounted within the interior of the stent frame to provide unidirectionalflow of blood through the prosthetic aortic valve; and a coveringmaterial fixed on an outside surface of the stent frame to enclose theinterior, wherein the covering material includes a plurality of cut-outsrespectively aligned with the plurality of cut-outs, openings orrecesses in the stent frame.
 8. The valve of claim 7 wherein thecut-out, opening or recess is generally U-shaped or V-shaped orgenerally square shaped.
 9. The valve of claim 7 wherein the cut-out,opening or recess is generally curved in shape.
 10. The valve of claim7, wherein the cut-out, opening or recess further comprises anindentation in the stent frame so the frame avoids compressing theconduction tissue.
 11. The valve of claim 7, further comprising at leastone radiopaque marker placed adjacent opposite edges of each of thecut-outs, openings or recesses to aid in the correct orientation of thevalve during implantation in relationship to the conduction tissue. 12.A prosthetic aortic valve for mounting at an implant site associatedwith a native aortic valve of a patient, comprising: a stent frameformed from wire, the stent frame including an upper margin or edge, alower margin or edge, and an interior, wherein the stent frame includesa cut-out, opening or recess located along the lower margin or edgeconfigured to align with conduction tissue below the native aortic valveto prevent contact by any structural element of the stent frame with theconduction tissue, at least one radiopaque marker placed adjacentopposite edges of the cut-out, opening or recess to aid in the correctorientation of the valve during implantation in relationship to theconduction tissue, and a plurality of prosthetic valve leaflets mountedwithin the interior of the stent frame to provide unidirectional flow ofblood through the prosthetic aortic valve.
 13. A method of implanting aprosthetic aortic valve, the prosthetic aortic valve including a stentframe formed from wire, the stent frame including an upper margin oredge, a lower margin or edge, and an interior, wherein the stent frameincludes a cut-out, opening or recess located along the lower margin oredge, and a plurality of prosthetic valve leaflets mounted within theinterior of the stent frame to provide unidirectional flow of bloodthrough the prosthetic aortic valve, the method comprising: insertingthe prosthetic valve into a native aortic valve, and aligning thecut-out, opening or recess with the conduction tissue located below thenative aortic annulus.
 14. The method of claim 13, further comprising:placing the prosthetic valve, in a collapsed condition, into a deliverysheath in a femoral artery of the patient with the prosthetic aorticvalve in a predetermined rotational orientation for ensuring that thecut-out, opening or recess is at least substantially aligned with theconduction tissue at the native aortic valve when the prosthetic valveis delivered into the native aortic valve.
 15. The method of claim 13,further comprising: using at least one radiopaque marker placed on theprosthetic aortic valve adjacent opposite edges of the cut-out, openingor recess to align the cut-out, opening or recess with the conductiontissue.
 16. A system to assist percutaneous aortic valve replacement,comprising: a prosthetic aortic valve movable between a collapsedcondition suitable for percutaneous delivery into a native aortic valve,and a guide device configured to engage native heart tissue and guidevalve deployment and expansion away from conduction tissue.
 17. Thedevice of claim 16, wherein the guide device is integrated with theprosthetic aortic valve.
 18. The device of claim 16, wherein the guidedevice is comprised of wire and takes on the form of at least one of: ahelix, a basket, and a plurality of radiating arms.
 19. A method ofimplanting a prosthetic aortic valve, comprising: using a guide deviceto identify the nadir of the aortic valve leaflets or the leftventricular outflow tissue, and percutaneously implanting a prostheticaortic valve having a valve frame so that no portion of the valve framecontacts conduction tissue located below the native aortic annulus. 20.The method of claim 19, further comprising: removing the guide devicefrom the patient through a catheter after implanting the prostheticaortic valve.
 21. The method of claim 19, further comprising: using atleast one radiopaque marker on the guide device and at least oneradiopaque marker on the prosthetic aortic valve to locate theprosthetic aortic valve relative to the guide device at the nativeaortic valve.
 22. The method of claim 19, further comprising: using theguide device, or a separate centering guide, to center the placement ofthe prosthetic aortic valve within the native aortic valve.